Hemp Growing

All Cannabis germplasm is completely interfertile, suggesting that the genus consists of a single species, with two subspecies and subsp. indica . Through DNA analysis, evidence pointed towards C. sativa, C. indica, C. ruderalis populations of Cannabis as being distinct subspecies of Cannabis sativa . Common vernacular terms, sativa and indica, have been used to describe different types of marijuana, causing much confusion for consumers who believe that these different forms of Cannabis happen to function in different ways. Generally, sativa types are plants with tall and slender morphology, narrow leaflets, and late maturation while indica types have shortened stature, broad leaflets, and early maturation . Whatever true population differences there may have been between indica and sativa types of C. sativa subsp. indica have become lost over generations of repeated hybridization events , although clearer population differentiation between hemp and marijuana still exist . Thus, industrial hemp is simply classified taxonomically as Cannabis sativa L. with low amounts of THC . One way to classify genotypes or populations of C. sativa is through their chemotypes, or chemical phenotypes, based on the predominant cannabinoids in the plant, in particular, cannabidiol , cannabigerol , and tetrahydrocannabinol . C. sativa is divided into five different chemotypes: THC dominant, referred to as the drug-type, CBD dominant, referred to as fiber-type, and one which THC and CBD are present in equal proportion. Two other chemotypes, CBG dominant and those which contain low concentrations of cannabinoids, are less frequently used in scientific literature . The classification of C. sativa germplasm with chemotypes enables scientists to easily classify individuals for breeding for certain uses like pharmacology, fiber, or seed . Cannabis sativa L. is a dioecious plant with individuals from the male and female sexes having distinct morphological differences .

Male individuals are described as slenderer in stature than their female counterparts and have less reproductive biomass compared to a females’ dense inflorescence . Differences in morphology, how to cure cannabis specifically between the sexes of hemp plants, only become apparent after the seedling stage . The genetic basis for sex in Cannabis is determined by the inheritance of either an X or Y chromosome from the male parent. Female plants have a sticky inflorescence that captures wind-dispersed pollen from male plants . Male flowers, within their hanging panicles, have a perianth of five sepals that surround the androecium; the anthers at maturity split lengthwise, releasing the pollen grains . Female flowers develop as thick clusters called racemes, and receive the pollen grains through insect, wind, or mechanical dispersion onto the pistils. In production settings, formation of seeds is undesirable if the use of hemp is the extraction of essential oils or the sale of the flowers themselves; consequently, most hemp producers prefer to grow only female individuals and avoid fertilization from male plants . Grandular trichomes, a form of sessile trichomes, cover the surface of female flowering tissues and produce cannabinoid oils . The secreted oils which burst from these trichome sacs coat the surface with a sticky resin, which results in flowers that are waxy in texture . Cannabinoids likely serve multiple purposes within the Cannabis plant, such as a defense response against herbivory from insects and the dissipation of heat stress in the environment. Cannabinoids are produced in substantially higher quantities when exposed to UV-B radiation , suggesting they act as a barrier against the damaging effects of UV-B radiation .

There are over 180 different cannabinoids present in C. sativa, with the primary cannabinoids being THC, also called Δ9-THC, CBD, and CBC . These cannabinoids coexist along with their acid-precursors: tetrahydrocannabinolic acid , cannabidiolic acid , and cannabichromenic acid . The acid forms of these cannabinoids change into their decarboxylated forms primarily from the application of lightand/or heat onto the harvested crop, but the decarboxylated forms still exist at certain levels within the flowering tissue before harvesting . All acid forms of cannabinoids come from a primary precursor phytocannabinoid called cannabigerolic acid . CBGA is a product of two metabolites, olivetolic acid and geranyl diphosphate, which are formed from the polyketide pathway and plastidial deoxyxylulose phosphate/methyl-erythritol phosphate pathway , respectively . Cannabinoids have been used as a component of human therapeutic medicine for thousands of years . Specific cannabinoids have been used to minimize chronic pain, improve sleep quality, and treat a wide variety of other ailments. C. sativa has obtained more attention over the last 30 years as a source of medicine in America after California passed the Compassionate Use Act of 1996, a bill which allowed the state to provide patients with access to medical marijuana “in the treatment of cancer, anorexia, AIDS, chronic pain, spasticity, glaucoma, arthritis, migraine, or any other illness for which marijuana provides relief” . Since then, there has been increasing interest in the use of cannabinoids as a way of minimizing pain, a malady affecting 1 in 5 Americans on a daily basis . CBD is of particular interest because it can provide pain relief without the psychoactive effects that come with other cannabinoids like THC .

The global value of CBD products is 2.8 billion dollars as of 2020 and is expected to increase on the order of 20-23% year-to-year over the next five years . In America, Cannabis was a widely grown crop for many years during the 18th and 19th centuries before being replaced by cotton as the predominant crop used for textiles . With increased interest in the crop medically for its oils, it has also renewed interest in its fiber , oil, and seed . Hemp bast, the long fibers from the outer stem of hemp, can be used to make carpets, shoes, diapers, insulation, yarn, composite materials, and plastics . The hurd, or inner core fibers of the hemp plant, can be used to create hempcrete, animal bedding, potting mix, and soil amendments . With a wide variety of uses, industrial hemp fibers, as of 2019, have a current market value of $4.46 billion with an expected compound annual growth rate of 33% through 2027 to total $43.8 billion . With the value of industrial hemp between its fiber and CBD products currently being valued at over $7.2 billion, there is increasing interest in agronomic improvements for the crop. Hemp is typically grown in field settings but can be grown in greenhouses when growers are focusing on greater pest control, year-round growth, and control of lighting regiment. In field settings, hemp generally is grown on well-drained soil which is high in fertility . Planting density varies among varieties and the grower’s intended use for the crop. Hemp grown for oil extraction requires wider spacing to promote branching and flower development; planting densities for the purpose of harvesting its fiber is typically double that of oil seed varieties, however, in general the architecture of the plant itself is strongly associated with the density of planting, nutritionally availability within the soil, and the length of day that the plant is exposed too during its life cycle . Hemp is either planted by direct seeding or through the transplantation of seedlings or clones . When hemp is grown for medicinal oil extraction, the field typically consists of only female plants. Usually this is accomplished by using “feminized” seed, which is produced from female plants that have been induced to produce male gametes and seed using either chemical or environmental stress which results in seeds which will produce seeds which result mostly in female plants . This process of masculizing female hemp plants on an industrial scale is done through foliar applications of silver thiosulfate . The rationale for producing feminized seeds, outside of maintaining genetically identical inbred lines for commercial sale, is to minimize the production of seeds within the flowering tissue of female plants due to consumer, grower, and processor preferences. Hemp improvement can be done through the use of phenotypic recurrent selection, aka mass-selection, by selecting the best individual plants based on field performance and using their seed for the next evaluation cycle . Once an elite variety has been developed, back crossing can be used to incorporate new traits from undesirable germplasm . For traits such as fiber quantity and quality, with high trait heritability, trimming cannabis mass-selection can work well . Other breeding practices have been employed for the purpose of either increasing variation, specifically when crossbreeding individuals, or for fixing a trait through inbreeding to produce inbred lines and/or to capitalize on heterosis of F1 hybrid cultivars .Advances in biotechnology can accelerate the incorporation of a trait into an existing population with high accuracy and speed using next generation sequencing and marker assisted selection .

Marker assisted selection works to track the phenotype of an individual plant by associating genetic polymorphisms with trait variation, enabling selection on seedling plants without having to grow the individual to maturity . Recent advances in sequencing technology, specifically with the development of next-generation sequencing , has reduced the price of sequencing whole genomes of individual plants , making marker identification and use more tractable. Day neutrality is a trait which is present in many agricultural crops such as soybeans, wheat, barley, rice, tomatoes, strawberries, and alfalfa . Several genes involved light sensing contribute to differences among genotypes in time of flower and in day neutrality; the major genes appear to be conserved across species. For instance, day-neutrality is controlled by CONSTANS , a gene which encodes a transcription factor involved in the transduction of light signals, promoting the expression of other genes downstream . The genetic basis for the change from vegetative growth to flowering within hemp cultivars is mostly unknown. Petit et al. , identified six QTLs related to genes which control the perception and transduction of light and their associated transcription factors. However, hemp germplasm has a wide range of flowering times, affected by both genetics and the environment . Hemp, Cannabis sativa L. is a valuable medicinal, fiber, seed, and oil crop. Understanding and manipulating the flowering time of hemp could facilitate cultivar development for diverse environments and cropping systems. The time at which hemp transitions from vegetative growth to flowering is critical for the development and quality of the final harvested product. Most hemp germplasm requires short days to begin flowering and producing seed, oil, and cannabinoid products . Before the transition to flowering can occur, a period of vegetative growth stage controlled by the accumulation of thermal time in the environment is necessary . Vegetative growth for hemp is optimal around 30o C and continues to a maximum temperature about 42o C. Around 300 to 600 units of cumulated thermal time over 1o C must occur for the plant to be able to initiate flowering if the critical daylength is reached . While typically a short-day plant, hemp germplasm has considerable variation in TOF . Some hemp germplasm has day-neutral flowering, which means that regardless of photoperiod, they will flower after a certain amount of thermal time has accumulated . Day-neutral Cannabis varieties can go from seed to flowering in a soon as four weeks, and some varieties can be harvested within 100 days after seeding. The trait for day-neutrality originated from the ruderalis variety of Cannabis sativa in parts of Southern Russia. These plants are described as being short and stalkyin nature, while producing small amounts of flower with low concentrations of THC . Despite its undesirable attributes, ruderalis has been used to introgress day neutrality into high yielding flower and oil varieties. The day neutral trait can provide significant agronomic benefits by standardizing harvest time and potentially enabling growers to have more harvest cycles in one year compared to those growing day-sensitive varieties of hemp which takes much longer to flower in most environments. The genetic basis for day neutrality, specifically in hemp, is currently unknown. We hypothesized that at least one major locus controls day neutral flowering with multiple minor loci affecting the variation in time to flower within day neutral or daylength sensitive germplasm. To test this hypothesis, we hybridized day neutral and daylength sensitive accessions of hemp and evaluated the progeny for flowering time across three field trials over two years in order and genotyped them using next generation sequencing technology to identify genetic loci involved in flowering time. Hemp seeds were placed into 72-cell flats containing potting soil mix, composed of mostly perlite, and were then covered in vermiculite and watered daily.

The remote and rugged terrain that once attracted illicit cultivation attempting to avoid detection may now hinder the ability of farms in these areas to comply with environmental regulatory standards and ultimately become licensed. Multiple environmental permits may be required in order to obtain a CDFA cultivation license if growing outdoors or in greenhouses, and the fees and information requirements may represent significant hurdles to some farmers . Initial evidence indicates the first wave of regulated, industrial scale cannabis has largely begun not in the historical epicenter of Northern California, but in the hills and isolated valleys of the Central Coast. Although select counties in the Central Valley have allowed a token number of large cannabis farms , licenses for farms of equivalent size have been issued en masse in counties such as Santa Barbara and Monterey . In these areas, it is not yet clear if large-scale cannabis farms will more commonly repurpose existing infrastructure or stake out new territory further from existing agriculture and closer to natural spaces. Understanding the potential environmental impacts of industrialized cannabis requires knowing where and why extensification or intensification occurs, patterns of natural resource use, and how these dynamics relate to regulatory mandates. For example, regarding the issue of water, the legacy of illegal cannabis cultivation sites and their tendency to divert from streams and springs has led to these sources of water becoming tightly regulated within the legal cannabis industry. In particular, air racking extraction from these sources is prohibited during the growing season and farms that rely on them must either instead collect and store this water in the off season or use an alternative source.

For the majority of regulated cannabis farms, the choice has been to use well water and this is already the most common source for irrigation . Given the hurdle of developing sufficient storage, especially at increasingly larger farm sizes, the use of wells will likely increase in frequency . While the story of groundwater depletion in California is common knowledge , the use of wells by commercial cannabis farms is fundamentally different, given their tendency to occur outside of large aquifer basins . Such wells that are located instead adjacent to watercourses, in small alluvial aquifers, or fractured bedrock have potential to reduce crucial stream flow during the summer months , although this topic is currently understudied and generally beyond the purview of current California groundwater policy . This is a concern not only for large-scale farms in the new frontier of the Central Coast, but also for farms on the North Coast that must compete with these operations. The prospect of farms on the North Coast increasing in size to compete and shifting to groundwater extraction to comply has latent environmental implications, deserving further research. Characterized by geographically isolated, small farms, the informal cannabis cultivation sector represented a form of agriculture distinct from California’s consolidated, credit-supported industrial model. The historic legacy of the cannabis industry in Northern California has differentiated this region and led to worldwide recognition of its products. However, remoteness has now isolated traditional cultivation regions from an emerging legal supply chain and new markets, while obligating farms to navigate high regulatory costs associated with operating in environmentally sensitive locations.

How farmers in these remote watersheds respond holds importance for the future of the cannabis industry and its socio-environmental dynamics. Formation of grower cooperatives , appellation systems , caps on farm size and license consolidation , or a return to medical provisioning collectives may provide tools to overcome steep start-up and licensing costs for small farmers. Due to ongoing federal prohibition, farmers do not have access to traditional supports such as bank loans or crop insurance and instead must rely on private capital, limiting engagement in legal markets by many smaller farmers. Paradoxically, if barriers to capital are reduced, it may invite institutional investment and accelerate further industrial consolidation and up-scaling. More research is needed to understand the socio-ecological dynamics that underpin changes in cannabis cultivation in California and beyond. California’s statewide legalization opens some research pathways through regulatory databases, harmonization among institutions and jurisdictions, and new funding mechanisms. Yet, federal prohibition still creates a “quasi-legal challenge” for robust research , with consequences for effective policy-making and environmental health . Federal prohibition can inhibit institutional funding , discourage participation of informants in studies , lead to suspicion of researchers by potential study participants , create difficulty for Institutional Review Boards and researchers to estimate and mitigate risks for human subjects, and create asymmetries in data collection and knowledge types. High numbers of producers operating outside of regulatory systems impede the ability for comprehensive and representative studies and projects limited to only “compliant” producers cannot account for the total socio-ecological dynamics of cultivation.

With a lack of robust research, resulting policies cannot be driven by direct research on cannabis, may impair social equity in the transition of informal producers to formal markets , and complicate implementation of strategies to govern common environmental resources . Further, policies that incentivize industrial consolidation and eliminate small producers may have environmental consequences . Among cannabis producers, decisions about production can alter ecological and hydrological conditions, requiring attention not just to stream flows, pest management, indicator species, and wildlife movement patterns, but also to the social calculus of decision-making. Analyses of production decisions necessitate the development of qualitative research methods to understand how policy formations, social norms, knowledge access, and enforcement practices, among other variables, shape production practices across different kinds of ecologies and regions. In particular, many farmers are electing to avoid compliance . Factors influencing non-compliance may derive from prohibition or may only emerge post-legalization . Understanding the perspectives of non-compliant farmers is crucial to researching the social and ecological dynamics of cannabis production. Equally important is a qualitative, political economic understanding of how and why policies take particular forms in certain jurisdictions at certain times. Which interests and groups are most and least influential in forming polIcy? Who bears the consequences and rewards of the resulting regulatory regimes? Rapid transformations in cannabis policy are corresponding to the emergence of new scales, practices, and ecological consequences of cannabis cultivation. Lessons from other legal forms of agriculture suggest that increased market pressures may lead to industrialization, extensification and/or intensification, and increased reliance on credit fueled by debt. Siting patterns described here indicate that all three may already be trending upward in California since legalization of production for recreational use. As changes rapidly occur, research is urgently needed to understand the relations between regulatory change, farm size, location, environmental outcomes, and the geographical distributions of benefits and impacts. Such analyses will aid policy maker’s ability to govern and farmer’s capacities to participate in this newly regulated industry. If done with an eye toward equitable and just outcomes, drying weed it may also point the way toward a cannabis agriculture that incorporates and learns from the lessons and failures of industrialized agricultural production. Assessing the environmental impacts of the cannabis industry in Northern California has been notoriously difficult . The federally illegal status of cannabis has prevented researchers from obtaining funding and authorization to study cultivation practices . Fear of federal enforcement has also driven the industry into one of the most sparsely populated and rugged regions of the state , further limiting opportunities for research. An improved understanding of cannabis cultivators’ water use practices is a particularly pressing need.

Given the propensity of cannabis growers to establish farms in small, upper watersheds, where streams that support salmonids and other sensitive species are vulnerable to dewatering , significant concerns have been raised over the potential impacts of diverting surface water for cannabis cultivation. The environmental impacts of stream diversions are likely to be greatest during the dry summer months , which coincide with the peak of the growing season for cannabis. Further, because cannabis cultivation operations often exhibit spatial clustering , some areas with higher densities of cultivation sites may contain multiple, small diversions that collectively exert significant effects on streams . An important assumption underlying these concerns, however, is that cultivators rely primarily on surface water diversions for irrigation during the growing season. Assessments of water use impacts on the environment may be inaccurate if cultivators in fact use water from other sources. For instance, withdrawals from wells may affect surface flows immediately, after a lag or not at all, depending on the well’s location and its degree of hydrologic connectivity with surface water sources . Documenting the degree to which cannabis cultivators extract their water from above ground and below ground sources is therefore a high priority. In 2015, the North Coast Regional Water Quality Control Board , one of nine regional boards of the State Water Resources Control Board, developed a Cannabis Waste Discharge Regulatory Program to address cannabis cultivation’s impacts on water, including stream flow depletion and water quality degradation. A key feature of the cannabis program is an annual reporting system that requires enrollees to report the water source they use and the amount of water they use each month of the year. Enrollees are further required to document their compliance status with several standard conditions of operation established by the cannabis program. These include a Water Storage and Use Condition, which requires cultivators to develop off-stream storage facilities to minimize surface water diversions during low flow periods, among other water conservation measures. Reports that demonstrate noncompliance with the Water Storage and Use Standard Condition indicate that enrollees have not yet implemented operational changes necessary for achieving regulatory compliance. In this research, we analyzed data gathered from annual reports covering 2017 to gain a greater understanding of how water is extracted from the environment for cannabis cultivation. The data used in this study was collected from cannabis sites enrolled for regulatory coverage under the cannabis program. The program was adopted in August 2015, with the majority of enrollees entering the program in late 2016 and early 2017. The data presented in this article was collected from annual reports submitted in 2018 , which reflected site conditions during the 2017 cultivation year. The data therefore represents, for the majority of enrollees in the cannabis program, the first full season of cultivation regulated by the water quality control board. Because the data was self-reported, we screened reports for quality and restricted the dataset to reports prepared by professional consultants. Most such reports were prepared by approved third-party programs that partnered with the board to provide efficient administration of, and verification of conformity with, the cannabis program. Additional criteria for excluding reports included claims of applying water from storage without any corresponding input to storage, substantial water input from rain during dry summer months and failure to list a proper water source. Reports containing outliers of monthly water extraction amounts were also identified and excluded due to the likelihood of erroneous reporting or the difficulty of estimating water use at very large operations. Extreme outliers were defined as those values outside 1.5 times the bounds of the interquartile range . Farms were not required to use water meters, and those without meters often estimated usage based on how frequently they filled and emptied small, temporary storage tanks otherwise used for gravity feed systems or nutrient mixing. The final dataset included 901 reports. Parcels of land where cannabis was cultivated — including multiple contiguous parcels under single ownership — constituted a site, and this is the scale on which reporting was conducted. The spatial extent of the cannabis program included all of California’s North Coast region ; however, only a subset of the counties in this region allow cannabis cultivation and therefore reports were only received from the following counties: Humboldt , Trinity , Mendocino and Sonoma . Because Sonoma County contributed relatively little data, we combined Sonoma County’s enrollments with those from Mendocino County when making county-level comparisons. The data used for this analysis included the source and amount of water that cultivators added to storage each month as well as the source and amount of water applied to plants each month. We did not analyze absolute water extraction rates. Rather, we used the amount of water extracted each month — whether water was added to storage or applied to plants directly from the source — to analyze seasonal variation in each water source’s share of total water extraction. Water sources included: surface , spring , rain , well , delivery and municipal .

By tracing the evolution of prohibition through its U.S. history I seek to show the roots of our current drug laws and the role of scapegoating, dichotomization, and racism in their passage. I begin the chapter with a brief review of relevant sociological literature and a short sketch of the historical development of prohibition, as drugs became the target of state and federal laws one by one. Next, I analyze the discourse of prohibition using conceptual tools from the sociology of affect. My goal in this chapter is to show the entrenched rhetoric and emotion of drug prohibition to give the reader an idea of the task confronting the drug policy reform movement. In chapter two I use in depth interviews, archival materials, and Internet research to trace the development of the drug policy reform movement. I theorize the movement as made up of three branches; marijuana law reform, harm reduction, and anti-prohibitionism. My analysis of the movement is guided by concepts from the social movement literature including insights and categories from Resource Mobilization theory. After a discussion of the historical context of the 1960s, I give an in-depth analysis of the development and decline of the National Organization for the Reform of Marijuana Laws in the 1970s. I use the categories of Resource Mobilization to emphasize the role of social movement organizations in the movement and to conceptualize the ways the various organizations in the movement relate to one another and funding sources as a social movement industry beginning in the 1980s. After a brief detour through the harm reduction movement in the late 1980s and 1990s, I trace the rise of the anti-prohibitionist branch and how it relates to the two earlier branches of drug policy reform.

I close the chapter with a brief description of the current state of the movement and the chief areas of concern for its participants. In chapter three I seek to highlight the sites of activity for the drug policy reform movement. My goal is to address a lack of focus on physical space and location in the social movement literature. This chapter sprang from my fieldwork and represents a foray into “grounded theory.” Using an ethnographic approach, I attended numerous conferences, hemp rallies, protests, how to cure cannabis and meetings to discover the importance of such sites to the movement. To theorize the role of such events I sought to build on the existing concept of repertoires of contention. I discuss some of he insights I gleaned from attending movement events, including points of contention, issue framing and the role of emotions. In chapter four, I use political process theory to analyze the birth of medical marijuana in the San Francisco Bay Area in the early 1990s. I theorize the unique political opportunity structures that gave rise to the early medical marijuana movement. Next, I highlight the role of resources, social movement organizations, and elite benefactors in the campaign to legalize medical marijuana at the state level through the Proposition 215 ballot initiative. Finally, I analyze the rise of dispensaries and trace their evolution from cannabis buyers’ clubs to medical cannabis dispensary collectives. I also examine the importance of dispensaries as sites of continued movement activity. Chapter five, “A Tale of Three Cities” looks at medical marijuana dispensaries and how the regulatory climate and political opportunity structures of three different metro areas in the state affect the number and type of dispensaries that take root. By looking at the varying experiences of San Francisco, Los Angeles, and San Diego with the regulation of medical marijuana, I analyze both the structure of political opportunities and the ways that activists alter those structures.

Using interview data, observations from attending City meetings, and official City documents, I focus on the ways that medical cannabis providers participate in the political process that affects them. Theoretically, this chapter builds a dynamic view of the concept of political opportunity structures. By looking at the variety of tools that activists use to change the opportunity structures they confront, this chapter also serves as a model for future drug policy reform activists. Chapter six looks at the transition of medical marijuana from a social movement to an industry and the way that the hybrid movement straddles the fields of activism and commerce. I argue that the hybrid status of medical marijuana is unique among social movements and an interesting site for empirical exploration and theory building. Hybrid status also brings significant tensions for participants, and these tensions have developed into pronounced fault lines and factions. As articulated by movement leaders in a series of panel discussions, the hybrid character of the medical marijuana movement and how it should relate to the wider movement for drug policy reform are hotly contested issues. Chapter six concludes by looking at how the state has recently responded to the drug policy reform and medical marijuana movements, and the prospects for drug policy reform in the future.To contextualize the goals of the drug policy reform movement, the opposition it faces, and the discourse that it is seeks to counter, I present a brief history of drug prohibition and an analysis of the “drug control industrial complex’” employs to generate support and insulate drug prohibition from change. After presenting relevant sociological literature and tracing the history of drug prohibition, I analyze the arguments, rhetoric, and imagery that proponents of prohibition have employed over its relatively brief history.

Central to my analysis is a discussion of the emotions that anchor prohibitionist discourse to its cherished subjects, and how Gordon’s concept of “haunting” can illuminate the workings of drug prohibition. The drug policy reform movement is essentially engaging in an argument with the proponents of prohibition about the merits of the approach. With the advent of the Internet, the proliferation of drug policy reform groups, and their increasing ability to represent reformist discourse in the mass media, participants in the movement are increasingly able to counter the powerful discourse of punitive prohibition. Additionally, as the number of medical marijuana dispensaries has grown, popular culture and news media have made their depiction a favorite subject. The drug policies pursued in the United States present a complex enigma. Penalties for use are among the most stringent in the world, yet Americans are more likely to use illicit drugs than people in comparable nations. The U.S. is also the most vocal and active exponent of global drug prohibition. The federal government remains adamantly opposed to drug policy liberalization, but states including California and Colorado allow and facilitate truly revolutionary approaches to the provision of medical cannabis. Why have policy makers and drug control agencies pursued an approach that favors supply reduction, over demand reduction or harm reduction? Supply reduction depends on police and prisons, whereas supply reduction rests on treatment and prevention. Why have drug policy actors used the criminal law and the punitive capacity of the state as the chief instruments of drug control? And why have drug policy actors depended on stigmatizing drug users to marshal support for the policies of punitive prohibition? Although these questions are addressed in this chapter, my overarching focus is how the sponsors of drug prohibition marshal support for its reproduction. Using theoretical insights from the sociology of affect, and my concept of “the means of representation” I analyze the longevity and seductiveness of prohibitionist ideology. The story of drug prohibition in the United States is complex and multifaceted. Several noted sociologists have analyzed aspects of this history. Gusfield examined the symbolic uses of alcohol prohibition, Becker looked at the role of “moral entrepreneurs” in garnering support for cannabis prohibition, while Duster looked at the shifting demography and consequent status of opiate addicts and the how morality becomes the province of legislation. In a 1978 article, Himmelstein dubbed these studies “drug politics theory.” Other historical analyses have emphasized these changes but focused on the role of individuals in the passage of prohibitionist legislation or argued for alternative historical processes than those posited by their predecessors . Although Spector and Kitsuse did not formally delineate the constructionist approach until the early 1970s, the work of Gusfield and Duster presaged the turn toward constructionism. Within sociology, constructionist approaches to drug prohibition are prominent among narratives about the origin and reproduction of drug prohibition. Reinarman and Levine explored the demonization of crack cocaine for political purposes, indoor grow methods while Beckett showed how politicians constructed drug problems to build consensus around the “hegemonic project” of curtailing the welfare state while increasing the carceral organs of the U.S. government. Reinarman argues that “drug scares” recur frequently in U.S. history and have several consistent components. Reinarman seeks to understand the “appeal” of anti-drug claims in a nation characterized by “recurring anti-drug crusades and a history of repressive anti-drug laws.” According to Reinarman, drug scares and repressive drug policies are distinct social phenomena that often share seven common components.

They are usually based on a “kernel of truth” subject to “media magnification [through] the routinization of caricature,” where worst-case scenario anecdotes are amplified and circulated. Drug scares are the work of mostly self-interested “politicomoral entrepreneurs,” expanding Becker’s concept to the peculiar political capital afforded to American politicians by appearing “tough on drugs,” with no risk of alienating donors or the electorate . By linking use of drugs such as peyote, opium, cocaine, and marijuana with widely unpopular and feared ethnic minority populations, drug control actors began the project of dichotomization and out-grouping that under-girds U.S. drug prohibition. With alcohol, opium and the local phase of cannabis prohibition, American drug control actors were essentially using the drug law to control ethnic minorities. Gusfield theorized that proponents of alcohol prohibition were engaging in “status politics” with wets. With opium and cannabis, others have argued that the regime of drug control was an alternative means of enforcing cultural discipline . According to Reinarman , during successive drug scares, professional groups played prominent roles by generating and controlling the “public definition of a problem.” Although “the media, moral entrepreneurs, and professional interests…[often inflate] extant kernels of truth about drug use” without a “historical context of conflict” the actions of such groups are not sufficient to generate drug scares replete with repressive legislation . The concept of “drug scares,” supports my analysis of drug prohibition and its discourse. I seek to deepen the analysis of these earlier theorists by using newer theoretical inroads provided by affect studies. Although historians trace the impulse to prohibit the ingestion of some psychoactive drugs to early European colonialism , policy makers did not install a formal system to eradicate the use of certain drugs until the dawn of the Twentieth century. The system of drug prohibition sprang from a confluence of interests between elements of the Progressive movement and the U.S. foreign policy elite . When combined with racism, xenophobia, and potent “drug scares” early prohibitionist ideology would be formalized to first prohibit the smoking of opium in Western states in the late 19th Century, alcohol in 1920, and cannabis in 1937 . Other drugs, including LSD and MDMA , would not be prohibited until the 1960s and 1980s. In the U.S. the strategy of drug prohibition has created a “regime of truth” that drug prohibition is necessary for the protection of the citizenry. As constructed through discourse, drug policy is an example of the nexus between knowledge and power par excellence. According to Foucault , “…it is in discourse that power and knowledge are joined together.” Discourses of drug use form the arguments upon which drug policies are built. Through policy, actors are able to naturalize and systemize “regimes of truth” that create subjects who are forbidden to use certain psychoactive drugs. Through the discourse of “punitive prohibition” and the representations it deploys, drug policies are legitimized and sustained. Proponents of drug prohibition, garner support for such policies by representing the discursive formation of punitive prohibition in popular media, professional literature and government reports. I term the various forms of mass media, professional literature and government reports the means of representation. The forms of media available to both proponents and opponents of prohibition have increased throughout the twentieth century. In addition to newspapers, pamphlets and books in the late 19th century, radio, television and the Internet have diversified the means of representation throughout the twentieth century.

Newly hatched larvae could survive two weeks on yolk reserves alone, but were capable of feeding immediately on Artemia salina if provided. Larvae were transferred to beakers of fresh, unfiltered seawater each day. All mortalities appeared due to a failure to completely shed their molt. Each stage, defined as the period between molting, lasted an average of 9 days, with specimens reaching the post-larval stage at day 35 at 11ᵒC. Both the morphological guide and the methods of egg incubation were utilized to guide the present experiment. In the second study from this era, John Wickins investigated the influence of food density, salinity, temperature, and stocking density on the growth rate and survival of P. platyceros. Larvae hatching from females were reared in environments of 13-16ᵒC and 30±1% salinity. Development to post-larva was achieved at 15-29 days, in contrast to the 35-day span for Price & Chew; this is likely due to the warmer culturing temperatures. The stocking density yielding the highest survival rate was 5 larvae per liter at temperatures 13- 15ᵒC. Other key observations were that the size of Artemia fed to larvae did not influence larval growth rate or survival, and while larvae were raised successfully at a range of temperatures, there is a possible trend of fewer post-larvae survivors with increasing egg incubation temperature .The final major study addressing spot prawn rearing built off of those above to define the environmental extremes in which P. platyceros can thrive. Reiterating the others’ findings, Kelly et al. observed the larval period to last 26 to 35 days at 9.5-12.0ᵒC. They also concluded that spot prawns show a maximum thermal tolerance of 21.0ᵒC and salinity tolerance down to 22%. Growth rate was increased in both larvae and post-larvae by supplementing Artemia nauplii with any of four unicellular algae species. Kelly et al. also includes extensive investigation of diets for enhancing post-larvae growth, metal greenhouse benches which can be an important reference for further analysis of aquaculture potential, but the scope of this study is limited to larval development.

The present study attempts to reaffirm that this species can develop in laboratory settings. Using an amalgamation of the environmental parameters and timelines defined above, spot prawn larvae were hatched from ovigerous females caught off the coast of San Diego, California and cultured to post-larvae . The current growth of the aquaculture industry in conjunction with the depletion of wild seafood stocks makes revisiting this prospective aquaculture species a timely endeavor. By culturing eggs to this critical developmental phase, this experiments aims to provide an updated assessment as to whether P. platyceros may be a viable native species for aquaculture along the Pacific coast. The filter screen of the kreisel was large enough to allow Artemia and powdered feed through to the outflow chamber. This made it impossible to conclude if water clear of food matter signified the larvae had consumed everything or if it had been flushed out. The water was typically clear before most feeds, regardless of the Artemia concentration in the prior feeding. Because of this, feed concentrations were increased to compensate for food lost through the filter and the 120k Artemia per day became a minimum guideline. For future, the filtering screen of tanks should be of a finer mesh so as to allow longer retention of Artemia. This may require more frequent tank cleaning, perhaps stressing larvae, but the tradeoff would be observation of true feeding rates, which is required for maximizing efficiency of feeding schedules and densities. Possible cannibalism was observed occasionally, potentially indicating insufficient feed levels. Victims were usually white or translucent in color, which made it hard to distinguish between a mortality or exuviate. Since many crustaceans ingest their exuviae, it is possible this was natural feeding behavior ; it is also possible that larvae were cannibalizing each other due to lack of satiety. The uncertainty of this observation and that this occurred in the presence and absence of food renders this inconclusive.

As Kelly and Price & Chew both observed that most mortalities occurred in ecdysis, it is likely that failure during the molting process caused mortality.In regards to investigating aquaculture potential, future research should include large scaler trials of laboratory rearing with a priority on higher stocking densities and food conversion ratios. Percent survival at higher densities is essential in determining farming feasibility. The developmental period observed here is within the faster end of the range defined in previous studies and it would be useful to know if warmer temperatures could speed up the process further without significant increase in mortality. This trial experienced a maximum temperature of 19.4ᵒC, with sustained 19ᵒC temperatures for up to seven hours. Though not quite at the 21ᵒC thermal maximum, this culturing environment was very different than their natural habitat. Local waters did not reach higher temperatures until about halfway through the trial, so it would be interesting to see what impact consistently elevated temperature has during earlier larval stages. Furthermore, limitations in tank design prevented observations of feeding rates or food conversion ratios. Another essential question for aquaculture is the source of new stock. It is unknown if female spot prawns spawn more than twice in a lifetime, which would result a high turnover of broodstock. Until farmed specimens reached female maturity at four to five years, broodstock would have to be supplied from the wild. It is prudent to learn more about the reproductive capacity of mature spot prawns in order to provide a consistent supply of hardy larvae. Can females spawn for more than two years? Can fecundity be increased or stabilized by environmental conditions or does it continue to decrease each consecutive spawning? Do specimens from San Diego have the same seven- to eight-year lifespan estimated in Alaskan prawns ? Will they spawn in captivity? These questions are critical in establishing any level of commercial production and would also provide valuable information for future management of the wild fishery.

Finally, Litopenaeus vannamei is currently the marine species shrimp with the greatest global production by mass . This results in a wealth of knowledge in regards to techniques for disease prevention, broodstock maintenance, and other marine species obstacles that will likely be applicable to spot prawns. Some of the procedures for the current study were directed by methods used with L. vannamei. Macrobrachium rosenbergii, known as giant river prawns, are a freshwater shrimp that is also farmed. Farming methods for freshwater species are very different, though of all shrimp species farmed at a commercial-scale, M. rosenbergii is genetically of closest relation to spot prawns. M. rosenbergii and P. platyceros are both of the infraorder Caridae, so this freshwater species may provide a stronger biological reference for production timelines and practices . It would be prudent to use both species in directing future research regarding P. platyceros.The medical marijuana movement began in the San Francisco Bay Area in the early 1990s in a climate of official repression. This movement represents the most successful branch of the forty-year old drug policy reform movement. Using oral histories, participant observation, and archival research this dissertation explores the genesis, growth, and transformation of the medical marijuana movement in California from 1990 until 2012. I theorize the longevity of prohibitionist ideology over the course of the twentieth century in chapter one. Chapter two narrates the social history of the drug policy reform movement and its three branches; marijuana policy reform, harm reduction, and anti-prohibitionism. The three branches are characterized by diversification, as new organizations form to pursue different areas of drug policy reform, and competition for funding, but they maintain cooperative relationships with each other. My ethnographic fieldwork uncovered three types of physical sites, rolling greenhouse tables which play important roles in recruiting, networking, and facilitating cooperation on campaigns. The context and political opportunity structures of the San Francisco Bay Area were crucial factors in the genesis of the medical marijuana movement, but that activism and civil disobedience were also necessary for the movement to form. Activists and organizations in the metro areas of San Francisco, Los Angeles and San Diego were able to shape different political opportunity structures that affected the regulation of medical cannabis dispensaries in each specific locale. Medical marijuana began as a social movement and then transformed into an industry by shifting from the field of social movement action to the field of commercial action. New types of participants, a perceived change in political opportunity at the national level, and a more prominent public profile typify this shift. The shift also contributed to a refocused federal campaign to dismantle the system of medical cannabis provision that activists and entrepreneurs built over the twenty-one year history of the medical cannabis movement in California.The four decades old drug policy reform movement is comprised of individuals and organizations working to liberalize drug policies and move away from the system of “punitive prohibition” that typifies current drug policy in the U.S. According to Blain this “campaign is a ‘movement’ in the sociological sense that it employs the conventional repertoire of contention .” Drug policy reform organizations have trained their efforts on a wide variety of policy arenas, including, marijuana decriminalization, needle exchange programs , medical marijuana, and decreasing the penalties for drug offenses. Over the years, the number of organizations has increased and the specific concerns of various organizations have fragmented. The movement is made up of advocacy and membership-based organizations , a shifting mass base, and wealthy benefactors. Although the movement is ideologically powerful and well funded, successful campaigns in the political arena are few and far between. The drug policy reform movement has encountered opposition from both parent groups opposed to drug policy liberalization , and, uniquely, resistance from government agencies such as the Office of National Drug Control Policy and the Drug Enforcement Administration. The various organizations in the movement focus on a variety of campaigns of local, state,and national scope, yet the two most successful forms of drug policy reform have been medical marijuana and needle exchange programs Medical marijuana has been the most successful form of drug policy reform. In early 2012, sixteen states and the District of Columbia, have laws that allow qualified people to use marijuana for medicinal purposes. Individual medical marijuana dispensaries, storefront locations that sell cannabis to qualified patients, operate openly in California, Colorado, Montana and Washington. Clandestine medical cannabis dispensaries have been opened in several other states including Nevada, Michigan and Oregon. Along with needle exchanges and safe injection facilities, medical cannabis dispensaries represent specific modalities of drug policy reform. Modalities are different from changes in drug laws and sentencing policies because they have a physical location and present an active challenge to prohibitionist policies. The drug policy reform movement uses a combination of legal change to alter drug laws it finds unfavorable and direct action to put new policy modalities in place. While legislative change occurs comprehensively through ballot initiatives and the adoption of new legislation, activists, organizations and providers institute change on the ground slowly through protracted interactions with law enforcement agencies and state and local governments.In the 1930s, Alfred Lindesmith became the first scholar to look critically at the harmful consequences of punitive drug policy. His work paved the way for later scholars who looked at the negative effects of a policy that some have characterized as “punitive prohibition” . In the 1940s, Mayor Fiorello LaGuardia of New York City organized a team of scientists to investigate the cannabis use and policy in the Big Apple in response to fantastic allegations put forth by the director of the Federal Bureau of Narcotics in the previous decade. In the 1960s and the early 1970s, sociologists Becker , Gusfield and Duster all looked at the symbolic content of drug prohibition and the role of social status in determining which types of drugs were prohibited. During the 1980s and 1990s, epidemiologists and other scholars concerned with the intersection of drug use and drug policy would develop the harm reduction approach in response to the AIDS epidemic . Beginning the 1990s, the racially discriminatory consequences of the war on drugs became a major area of inquiry for scholars of drug policy .

In cases where the carrying distance is short , simply using the EL should provide an effective means for reducing the risk of LBD during bucket handling. The results of the manual handling of buckets during this study agree with the findings reported by Allread et al. , who showed the LBD risk for youth handling buckets ranged between 29 and 70% depending on the task and material handled . That study highlighted the need to develop interventions to address jobs that place youth on farms at increased risk of LBDs, including bucket handling. The proper deployment of the two interventions introduced in this current study is expected to provide sizeable LBD risk abatement for youth who commonly handle buckets on farms. Although the study showed the potential benefits of the EBC and EL in bucket handling tasks, the results produced relatively conservative intervention evaluations because of the limitations inherent in the design of the experiment, including the age and limited working experience of the subjects. The study included only 16 and 17 years old high school students and younger adult college students who were not experienced bucket handlers working on farms. This may limit the implications of the study results; however, it is also important to note that the participants were neither experienced with the use of the newly introduced interventions; therefore, the relative comparison among the methods should hold. The study focused on the risk of LBD during handling of buckets and did not consider the effects of manual handling or the two interventions on other joints of the body such as the hands/wrist or shoulders. However, rolling greenhouse benches the design criteria for the interventions attempted to consider the effects of these tools on the wrists and shoulder by properly designing the handles and adjusting the devices in accordance to the user’s anthropometry.

Further study should confirm whether these new tools may create new risks to other joints of the body, beyond of what is expected during manual handling. Furthermore, this study focused primarily on the physical risk factors contribution to LBD risk during handling of buckets. Factors such as physical immaturity, growth, and psychosocial factors among youth users might be possible sources of variations in injury risks and patterns. Lastly, improvements and redesign of the EBC and EL are needed so that they may become available to the general public and bring the expected benefits to their users. Considerable resources are spent on sundry health promotion strategies ranging from special diets to social networks to communing with nature to wrist-monitored step counts. But which core interventions are most effective and will produce meaningful health benefits? The evidence supporting much health advice is correlational and piecemeal; the field could benefit greatly from the rigorous research methods and theories of experimental health psychology. This article investigates community gardening for health promotion and presents some of the first well-controlled experimental research conducted on the topic. Community gardening is the practice of group cultivation of fruits, vegetables, and/or ornamental plants; it is widely used in a variety of settings but lacks empirical evidence of when, why, and for whom it promotes health. Community gardening is an especially promising platform to study real-world pathways to health and well-being because it is a deeply rooted, multifaceted intervention that has the potential to slowly shift people onto a healthy trajectory. Community gardening requires persistence, planning, accountability, physical activity, and cooperation with others.

There is significant theoretical and empirical reason to expect that each of these elements may lead to new, healthier psychosocial patterns. That is, in addition to harvesting the direct benefits of garden labor—fresh produce, exercise, and a close-to-nature scene—gardening may reinforce productive patterns in other areas of life. Research on gardening and health is usefully categorized into five general domains: diet, education, environmental stewardship, social competence, and psychological well-being . First, with regard to diet, gardening can lead to increased vegetable intake . Relatedly, gardeners have a lower average body mass index than non-gardeners —perhaps because of the combination of a healthy diet and physical activity that gardening reportedly promotes . Second, regarding education and cognitive development, school gardens show promise for engaging students in academics and improving test scores, especially in science-based subjects . By teaching biology, math, or even history using hands-on examples in the garden—a setting where students can move and interact— teachers may encourage deeper learning than in a traditional classroom. Third, many school garden programs have a focus on the environment, which fosters ethical and political interest in protecting the earth . Fourth, various social benefits of community gardens have been documented: gardens may facilitate social capital , collective efficacy , and social support . In other words, gardens can strengthen the local social fabric. Finally, gardens may enhance individual psychological well-being . Gardeners report that gardens promote relaxation, creativity, and restoration , and gardeners have been shown to score higher in eudaimonic well-being and quality of life than non-gardeners . One of the few true experiments on the effects of gardening found that after a stressful task, a gardening group exhibited reduced cortisol levels and reported improved mood above and beyond a reading control group .

Much of this research, however, is correlational, weakly controlled, or narrowly targeted. For example, most gardening studies to date lack random assignment, thus undermining confidence that observed effects are due to gardening rather than preexisting differences, self-selection, varying situations, or other confounds and artifacts. Second, many studies do not include baseline measurements, thus limiting the precision of assessment. Third, typically only the immediate effects of gardening are measured, overlooking possible long-lasting, fundamental shifts that might change a lifestyle and thus have a more meaningful impact on wellness. In short, there is a need for true experiments of gardening that comprehensively measure lasting effects. Perhaps the most complex and challenging limitation in the extant literature on gardening is the dearth of adequate comparison groups—a key to in-depth understanding of the effects of gardening. Many studies focused on dietary impacts of school gardens have properly used nutrition education as a control group, but there is a remarkable lack of adequate comparison groups in studies of effects beyond school gardens and diet. Including proper control groups is critical to understanding causal pathways— what it is about gardening that might drive the beneficial effects. Are the effects due to being active? Being outdoors? Growing something? Simply participating in a supervised activity? Such deeper understanding is necessary both for refining the psychology of health promotion and for designing effective interventions.Impervious land cover, habitat degradation and modification, and fragmentation spur biodiversity loss within urban areas . Yet, depending on local or landscape characteristics, urban habitats may support taxonomically and functionally rich communities of arthropods and associated ecosystem services. The relative importance of local and landscape drivers of urban biodiversity varies for different organisms, such as arthropods. At the local habitat scale, arthropod abundance and species richness increase with plant richness and woody plant presence. At the landscape scale, natural vegetation cover enhances arthropod abundance and species richness. In contrast, impervious surface negatively affects arthropods, including pollinators and natural enemies. Species life history and functional traits—phenotypes that affect ecosystem processes—can also determine how local and landscape scale changes in urban environments drive community formation. Feeding habits, habitat preference, body size, commercial drying racks and dispersal ability are traits that may be vary in sensitivity to local and landscape factors. For example, changes in leaf litter differentially affect cavity and ground-nesting bees. Increases in impervious cover more strongly affect light-preferring than xerophilous spiders, and negatively impact spiders with high dispersal ability . Thus, landscape-scale urbanization and local habitat management can selectively filter for certain traits, thereby structuring urban communities. Changes in both taxonomic and functional richness and the traits of individuals within communities are important to monitor because arthropods provide ecosystem services. Thus, understanding to what extent local and landscape factors affect arthropods informs both conservation and function. Beetles are abundant, diverse, and play important roles in urban ecosystems, but carabid diversity and community composition vary along urban to rural gradients and carabid functional traits vary with local and landscape factors. Beetles are natural enemies, detritivores, and bio-indicators of ecosystem-level processes. In particular, ground beetles are sensitive to environmental changes, taxonomically and functionally diverse, easy to sample, and are often used in ecological research. Carabids respond to changes in landscape forest cover and to local agroecosystem management, such as hedgerow or field margin planting.

As carabids might positively respond to intermediate levels of urbanization, urban ecosystems may conserve relatively high species diversity when compared to more natural habitats. Carabid traits and landscape connectivity and quality influence the dispersal and distribution of carabids , influencing habitat colonization across urbanization gradients. Individual carabid species have three types of wing development and dispersal ability: monomorphic brachypterous ; monomorphic macropterous ; and, dimorphic or polymorphic. High dispersal species are common in farms, prairies, and highly disturbed habitats, and low dispersal species are associated with older, less disturbed habitats. Smaller carabids may disperse farther, depending on wing morphology, and they are more abundant in areas with highly degraded, modified, and fragmented habitats. Yet, in agroecosystems, larger carabid species consume more prey and provide better pest control. Thus, environments with fewer large carabids may experience less pest control. An impervious surface may be an environmental filter of carabid functional traits, like body size, but less is known regarding how local management and landscape surroundings affect carabid activity, species richness, and functional traits in urban ecosystems. Urban agroecosystems provide an ideal system to examine the drivers of carabid taxonomic and functional diversity, community composition, and traits. Differences in urban habitat composition and structure influence carabid activity, diversity, and may result in changes in the abundance of beetles with certain traits . Although urbanization generally leads to biodiversity loss, it is important to determine what urban habitats, and which characteristics of those habitats, can support biodiversity conservation in the future. To this end, we compared activity density, species richness, functional group richness, and traits of carabids in urban community gardens that differ in local and landscape features. In order to determine how gardeners might promote carabid activity and taxonomic and functional richness for conservation purposes or to promote ecosystem services that are provided by carabids, we examined: Which local habitat and landscape features of urban, community gardens influence carabid activity density, species richness, and functional group richness? and, Which local habitat and landscape features of urban, community gardens influence carabid community and trait composition?We sampled carabids with pitfall traps for 72 h in each site monthly . The pitfall traps indicate carabid beetle activity density, not necessarily abundance. Pitfall traps were made of 12 oz. clear plastic tubs . We placed traps at the center of the 20 × 20 m plots in two rows of three traps, and separated each trap by 5 m. We buried traps flush to the soil level and filled traps with 200 mL of a saturated saline solution with a drop of unscented detergent to break the surface tension. We placed green plastic plates over each trap and elevated plates 7–8 cm above the ground with nails to limit the rainwater influx and to capture non-target taxa. Upon collection, we rinsed arthropods with water, separated them to order, and then stored insects in vials with 70% ethanol. Our sampling effort was unfortunately not as high as some other studies that examined carabids along urbanization gradients. We placed pitfall traps in active garden beds . Thus, we were unable to leave traps out for longer than 72 h or to get permission for putting traps more than three times during the summer growing season. KWW at the Essig Entomology Museum at the University of California, Berkeley , used published keys and descriptions and a comparison to authoritatively identified specimens in EMEC to identify the beetles. Nomenclature follows Lorenz . For each individual, we measured body length and grouped beetles into small and large size classes. We determined the flight wing morphology for each beetle by lifting the elytra under a dissecting microscope and noting wing state.

Samples are collected on an annual basis as part of the national disease surveillance programme, and consist of pooled organ homogenate supernatants which are then stored at −80◦C. In these samples, PMCV was first detected from broodstock fish on a marine site in July 2009, with infection in 100% of the pools . It was later detected in December of the same year in 100% of pools of broodstock fish at a second broodstock farm. These are subsequently referred to as the index cases, to be used as the starting point for simulation of the epidemic. The rationale behind setting these two farms as index cases is that they are the earliest detections , and do not seem to be epidemiologically connected. There were 9 parameters in the SIE compartment model . Following the approach used by Widgren et al. , and for model parsimony, the shed rate α was fixed at 1.0 per day, thereby defining the unit of the environmental infectious pressure variable ϕi. In the absence of more detailed data, it was assumed that the threshold for two seawater farms being connected by local spread was an euclidean distance of 10 km. It was further assumed that freshwater farms were not connected via local spread but only via fish movement. In the model, four event types were defined. “Enter” concerns hatchings and international imports. “Internal transfer” occurs on the day that individual fish change their age category, from egg-juvenile to smolt, or from smolt to growth-repro. “External transfer” occurs when fish move from one farm to another. “Exit” is linked with slaughter, cannabis grower supplies euthanasia or international export, and from this point these fish are no longer included in the simulation.

Each of the scheduled events was executed in the model once the simulation, in continuous time, reached the time for any of the events. Individuals were sampled at random from the compartments affected by the event. For example, for an external transfer event of n smolt from farm 1 to farm 2, n smolt were randomly selected from all smolts in farm 1 and placed into the same compartments in farm 2. Fish that entered the model were assumed to be susceptible in their respective age category. Imported fish were assumed to be susceptible, noting the aim of the study to explore spread in Ireland without considering international importation of PMCV. On average, 2,176,111 eggs were imported per year during the study period, according to information from the Irish Marine Institute . Fish remained in the same infection state whilst changing age category, from egg-juvenile to smolt or smolt to growth-repro, or moving between farms. Figure 1 presents the conceptual SIE compartment model for PMCV spread in farmed Atlantic salmon, including indirect transmission via the environment and fish movements between holdings. There is an EU legal requirement for aquaculture production businesses to be registered, and to keep records of all movements of aquaculture animals and products, both into and out of the farm . In Ireland, the storage of these movement data is undertaken by the MI. This database contains several variables, including the date of fish movement, origin and destination sites with geographic coordinates, life stage, species and quantity of fish moved. The present study was based on all fish movement reports to the Fish Health Unit of the MI covering the period from 1 January 2009 to 23 October 2017. This included 648 reports, with information about the identifier of the origin farm, identifier of the destination farm, the number of fish and age group and the date of the movement. Each record was linked to the geographical coordinates of the farms provided by the aquaculture production business records, to allow for incorporation of local spread during the modeling phase of this study.

A farm was considered “active” if any fish were present on the farm, according to movement records. The following data processing steps were used to generate events for the simulation. Enter events, i.e., hatchings or imports , were imputed as needed to ensure that farm-level fish numbers were sufficient to allow fish shipments between farms as recorded in the fish movement database . The date of the imputed hatching events was calculated based on the average residence time of fish prior to shipment in the farm. In total, 90 enter events were imputed, including approximately a third of these during the first year of the simulation . This represented on average 10 imputed enter events per year. Most of this imputed enter events corresponded to eggs or juvenile fish , but some fish were entered as smolts , growth , or broodstock fish . Internal transfer events, i.e., moving from egg juvenile to smolt or from smolt to growth-repro, were imputed when the relevant time during the simulation had been reached. When moving from egg-juvenile to smolt, fish were aged a week prior to shipping to seawater farms, and for aging from smolt to growth-repro, smolts were allowed to remain on the farm for 180 days. Exit events, i.e., mortality, slaughter, or euthanasia, were generated either the day prior to the last shipment of a fish cohort, when it was evident, based on the records, that the fish destination of the whole cohort was another farm , or after a fixed amount of time if it was clear from the records that the farm was the final destination of the fish . The duration of this period was 300 days in freshwater farms and 600 days for seawater farms. Broodstock fish in freshwater farms were assumed to live until 1 week prior to an egg shipment. A total of 55 unique farms were used for the simulation, with the following event types: enter, including reported imports , internal transfer , external transfer , and exit . A time-series was created to explore seasonality in the input data, focusing on the number of events, the number of farms with at least one fish and the number of fish per age category. A further time-series was produced to investigate the proportion of farms connected to at least one other farm, for each month of the year. A smoother was added to each of these time-series, using local polynomial regression fitting in order to describe the temporal trend . The disease spread model was implemented in SimInf , which is an R package for data-driven stochastic disease spread simulations. This package was adapted, in part, from the Unstructured Mesh Reaction–Diffusion Master Equation framework . It interfaces high performance compiled code and OpenMP, which allows work to be divided across multiple processors and computations to be performed in parallel. The disease spread simulations were performed using the SimInf package version 5.1.0 and R version 3.4.2. The simulation was initiated by first supplying the model with an initial state in every farm, together with all events.

At the outset, infection prevalence was assumed to be zero, since the earliest detection of the agent in the country, dry racks for weed on archived broodstock samples, was in July 2009 . The initial environmental infectious pressure, ϕi, was also set to zero, as it was assumed that PMCV was not present in the country at the time of initialization . Based on test results on archived broodstock samples , the introduction of the agent was assumed to have occurred in two separate occasions at two different farms: 1 month prior to the time of sampling of the first positive archived sample in the population of broodstock fish resident in the farm at the time of sampling, and a second time in November 2009, affecting broodstock fish in a broodstock farm where it was later detected in December of that year.With the final model, farm and fish PMCV prevalence were estimated on a daily basis following the simulated introduction of the agent. The spread of the agent was plotted as a time series and the modeled epidemic curves were described. The role of both local spread and fish movement was evaluated by setting either D to zero , or moving all fish shipped to the susceptible compartment at the time of shipment .In addition, we evaluated the effectiveness of an improved bio-security in specific farms. For the purposes of the simulations, our definition of bio-security refers to measures that prevent infected fish from entering a farm, akin to a bio-security strategy that is 100% effective in preventing infected fish from entering or leaving a farm. As described above, this was done by moving all fish shipped to the susceptible compartment at the time of shipment. Six strategies were tested. In the first strategy, all farms were targeted for an increase in bio-security. This would be a very costly approach, but a good ideal for comparison. In the remaining strategies, we targeted the 8 most central farms in terms of a specific farm centrality measure, which were indegree, outdegree, incloseness, outcloseness, and betweenness,using the same methodology described previously by Yatabe et al. . The sample size was chosen arbitrarily, representing ∼25% of farms in Ireland at that time. Briefly, indegree describes the number of different farms from which a farm receives fish, outdegree describes the number of different farms to which a particular farm sends fish, incloseness is an estimate of how close all other farms reach to a respective farm, outcloseness is an estimate of how close a respective farm reaches to other farms, and betweenness is a measure of the degree to which a particular farm falls on the shortest path between all pairs of farms in the network . For estimating these centrality measures, at the beginning of every year the movement records from the preceding 2 years were used for estimation. For example, on 1 January 2011 centrality measures of all farms were estimated based on fish movement data from 1 January 2009 to 31 December 2010, farms were ranked and the top 8 for each centrality measure were selected for an increased bio-security. There were two exceptions to this 2-year window for estimation of centrality measures: the year 2010, where only the data from 2009 was used to estimate centrality measures, and 2009, where no data from previous years were available. Therefore, during this latter year no control measures were applied. The former six strategies were evaluated using two approaches for preventing the spread of a newly introduced agent into the country: firstly, by applying the control measures 1 month after the agent was first detected , from now on the ‘reactive’ approach, and secondly by applying the control measures as a standard practice from before the first detection of the agent , from now on the “proactive” approach.Based on the data available for 2009, a rapid increase was observed that year in the number of active farms and fish . However, this is an artifact as many farms had not yet been involved in fish movement and thereby appeared inactive . As a consequence, our results are reported from the start of 2010. The number of active farms declined slightly during the period 2010–2017 with relatively stable numbers during the 2010-2014 period, and a decrease during the 2015–2017 period . The total farmed Atlantic salmon population in Ireland had an increasing trend from 2010, with a peak of more than 32 million fish in early 2015, to later decrease until the end of the simulation, although not dropping to previous levels, where it reached ∼13 million fish. This increase was related to a large increase in the number of juveniles during 2014 and 2015. The number of fish within each age category varied seasonally, with juvenile fish showing peaks during winter and dips during autumn , the former associated with spawning and the latter with the transition of juvenile fish to smolts prior to stocking in seawater farms in autumn and spring. For the smolts, the converse was true, with peaks during autumn and spring. This age group decreases roughly every 180 days, as this is the amount of time after which they were aged into the growth-repro age group. This in turn determines the peaks of this latter age group. The reduction in the numbers of fish in the growth-repro age group were mainly in spring-summer and autumn-winter, being a mixture of elimination of fish stocked in a farm as smolts after 600 days and elimination of fish stocked at older ages after spending the mean residence time in the farm .

The second peculiarity of the entry process is the existence of a matching stage where upstream entrants and downstream entrants form vertical relationships and decide on API trade. While in principle such a stage can be built into the econometric model, the incremental benefit from doing so is unlikely to compensate for the computational difficulty that it entails. Therefore, I assume that matching in the API market takes the following simplified form: every upstream entrant, including the upstream plants of vertically integrated entrants, is matched with every downstream entrant including units belonging to vertically integrated firms. In other words, every downstream unit is entitled – from a regulatory point of view – to use the API produced by any of the upstream units. Once we ignore patent challenges and allow every upstream entrant to be matched with every downstream entrant, the generic entry process can be characterized as a simple simultaneous-move game with discrete actions. Potential entrants choose their actions and receive payoffs according to the oligopoly game played out in the resulting vertical market structure. I do not explicitly model how firms trade the intermediate good and compete against each other in the post-entry vertical oligopoly; the effects of such interactions among firms are summarized into reduced-form payoff equations that have the actions of rival potential entrants as arguments. For a firm that is a potential entrant in the downstream segment but not in the upstream segment, the action set is {Not Enter, Unintegrated Downstream Entry}. Similarly, a firm that is a potential upstream entrant but not a potential downstream entrant has the action set {Not Enter, Unintegrated Upstream Entry}. Finally, grow vertical the choice set of a firm that is a potential entrant in both segments is {Not Enter, Unintegrated Downstream Entry, Unintegrated Upstream Entry, Vertically Integrated Entry}.

It is assumed that only pure strategy Nash equilibria of the entry game are played. Therefore, market structure outcomes that are not pure strategy Nash equilibria – for example, one unintegrated downstream entry and no other entries, or one independent upstream entrant and no other entrants – are ruled out. Elberfeld shows that vertical entry games are characterized by multiple equilibria even if entry decisions in one vertical segment are made prior to those in the other segment. This implies that the existence of multiple equilibria is an unavoidable aspect of simultaneous-move vertical entry games. Before moving on to the empirical analysis, let us briefly consider the motives for, and effects of, vertical integration in the generics industry. A former executive at Sandoz, one of the largest firms, mentions lower API costs, earlier access to APIs, and stability of supply as the advantages of vertical integration . Others have mentioned the possibility that vertical integration allows better control over the information flow between segments as well as better risk-sharing , which would presumably lead to higher levels of productive investment. These point to the existence of efficiency effects generated through vertical integration. Such effects are likely to benefit final consumers through lower prices, more reliable supply of drugs, or higher product quality. On the other hand, recent antitrust cases suggest that vertical integration can generate anticompetitive foreclosure effects. In FTC v. Mylan et al. , the Federal Trade Commission claimed that an exclusive dealing contract, signed between a finished formulation manufacturer and its upstream supplier, regarding the APIs for lorazepam and clorazepate tablets contributed to price increases of between 1,900 and 3,200 percent for the downstream product.7 Unlike exclusive dealing contracts, vertically integrated entry in the generic drug industry is not subject to antitrust scrutiny.

As a result, such anecdotal evidence on foreclosure effects is not readily available in the case of vertical integration. There is, however, no reason to assume that vertical integration cannot have similar anticompetitive effects.8 Estimation of the model is based on a maximum likelihood framework. At each iteration of the parameter search, I calculate the probability that the market structure observed in each of the sample markets is an equilibrium of the entry game. Loosely speaking, the likelihood contribution of a market is calculated by integrating over the region of the error term vector where the observed market structure is predicted as an equilibrium. Thus, the first tool we need is a mapping from the error term vector to equilibrium market structures. I implement the mapping by programming an equilibrium finding algorithm. The error term vector in my model has fairly high dimensionality and the region of integration is expected to have a complex shape. As a result, we can expect no closed-form solution to exist for the market structure probability. I therefore approximate the integral using a simulation-based method in which draws of the error term vector are taken . For each draw, the equilibrium finding algorithm is run to see if the market structure observed in the data is predicted as an equilibrium . The market structure probability is approximated by calculating the proportion of the draws for which the observed market structure is an equilibrium. In general, vertical entry games are characterized by multiple equilibria . Therefore, the equilibrium finding algorithm often indicates more than one market structure as a possible outcome of the entry game in a given market. When such equilibrium multiplicity occurs, an additional assumption is required in order to assign a unique value to the probability that the observed market structure is generated by the model.18 One possibility is to assume that the equilibrium with the highest joint profits is always realized.. Alternatively, one can specify an equilibrium selection function whose arguments consist of the characteristics of each equilibrium, such as whether or not it is Pareto dominant . Following Bjorn and Vuong , I employ the simpler rule that when there are multiple pure strategy equilibria, each market structure has the same probability of occurring. The entry game for each generic drug market involves a large number of heterogeneous players, which makes the equilibrium finding algorithm time-consuming. Even if one has a fast algorithm, the large number of evaluations that are required during estimation suggests the need to economize on the number of runs of the algorithm. To this end, I employ the method of importance sampling with change-of-variables . The advantage of this method is that the equilibrium finding algorithm needs to be run only once during estimation. In the remainder of this section, I describe the equilibrium finding algorithm, the simulation-based approximation of the market structure probability, and the importance sampling with change-of-variables method.As mentioned at the beginning of Section 2.5, there are 128 generic drug markets that satisfy the following criteria: the market opened up to generic competition during 1993-2005; the downstream product is the first one, among all single-ingredient products using the same API, to become generic; the downstream product is an oral solid, injectable, or topical formulation; and data on market characteristics are available for the product. These are the markets where we are likely to see upstream and downstream entry decisions being made at around the same time. 43 of the 128 markets are subject to a patent challenge by one or more of the generic entrants. These are identified by the Food and Drug Administration’s list of drug markets where one or more Abbreviated New Drug Applications containing a paragraph IV certification have been filed. As discussed in Section 3.3, the existence of a patent challenge changes the market structure formation process from a simultaneous-move entry game to a race to be the first-to- file entrant. Meanwhile, my econometric model is only designed to estimate the parameters of a simultaneous entry game. Therefore, the 43 markets with paragraph IV certification are dropped from the analysis. This leaves a sample of 85 markets that are not subject to patent challenge by any of the entrants. The exclusion of paragraph IV markets raises concerns of sample selection.

If the incidence of paragraph IV certification is correlated with any of the error terms of the model, vertical grow systems the removal of paragraph IV markets from the sample may lead to biased estimates. While acknowledging the importance of such concerns, the estimation conducted in this chapter does not take them into account. The main reason is the difficulty of incorporating selection into the econometric model. As in Chapter 2, sample selection can be modeled by specifying a dichotomous choice process for the determination of paragraph IV status at the market level, and allowing the error term in the paragraph IV equation to be correlated with the remaining error terms of the model.27 In practice,however, I find that the parameter estimates fail to converge when joint estimation of the vertical entry model and the paragraph IV equation is attempted.28 Another factor that may allow us to ignore the sample selection problem is that, according to the results in Chapter 2, the error term of the paragraph IV equation is not likely to be strongly correlated with the error terms of the firm-level payoff equations.29 The definition of downstream and upstream market entry follows that in Chapter 2. Downstream entry into market m is observed when a potential entrant’s ANDA for that market is approved by the FDA. Upstream entry is observed when the potential entrant’s submission of a DMF for that market is publicized by the FDA. Vertical entry occurs when the potential entrant receives ANDA approval and submits a DMF in the same market. The definition of potential entrant status also follows from Chapter 2. A firm is a potential downstream entrant of market m if its previous entry into the downstream segment of another market was less than five years before the market opening date of market m. 30 Similarly, a firm is a potential upstream entrant if its previous upstream entry in another market was not more than seven years before the market opening date. If a firm is both a potential downstream entrant and a potential upstream entrant, it is considered to be a potential vertically integrated entrant. Table 3.1 shows summary statistics for the number of potential entrants and the number of actual entrants in each market. The number of potential upstream entrants is greater than the number of downstream entrants. On average, there are 75.859 potential upstream entrants in a market while the average number of potential downstream entrants is 30.635. 18.929 of those entrants, on average, are potential vertically integrated entrants. The actual number of entrants is much smaller: an average market structure contains 3.365 unintegrated downstream entrants, 3.565 unintegrated upstream entrants, and 0.647 vertically integrated entrants. The estimated coefficients on the two continuous market characteristics, User Population and Per-User Expenditure, are largely within expectations. User Population has a significantly positive coefficient in the unintegrated downstream payoff equation, while in the other equations its coeffi- cient is not significantly different from zero. The Per-User Expenditure variable is not significant in the unintegrated downstream and vertically integrated payoff equations, but it has a significantly positive coefficient in the unintegrated upstream payoff equation. These results support the notion that larger market size and higher willingness-to-pay raise firms’ entry incentives. The dichotomous market characteristic variables have contrasting effects in the three equations. The Gastrointestinal/Endocrine-Metabolic dummy variable has a significantly positive impact on unintegrated downstream payoffs but its effect on vertically integrated payoffs is significantly negative. This conforms to the finding in Chapter 2 that vertical integration probabilities are lower in markets belonging to the gastrointestinal and endocrine-metabolic classes. It may be because the tighter control over upstream manufacturing processes afforded by vertical integration is less important for such drugs than for other drugs. Another finding that agrees with the results in Chapter 2 is that the Injectable dummy variable has a significantly negative coefficient in the unintegrated downstream and upstream equations, while its coefficient in the vertically integrated equation is significantly positive. This confirms the intuition that tighter manufacturing controls through vertical integration are more important for injectables than for other dosage forms. The Post-2000 dummy variable follows the same pattern as the Injectable dummy: it is significantly negative in the unintegrated downstream and upstream equations while being significantly positive in the vertically integrated payoff equation. One possible explanation comes from the finding in Chapter 2 that vertically integrated entry became more common after the year 2000 .

It is unlikely that Mylan and Watson were slower than their rivals at noticing the efficiency effects of vertical integration, given their long histories and large scale of activities. More plausibly, their decisions were made in response to the expectation that generic drug markets were going to become increasingly vertically integrated. The next section discusses how we can test the two leading explanations for the increase in vertical integration within the generic pharmaceutical industry: the existence of bandwagon effects, and the importance of relationship-specific investments to support patent challenges.In the existing theoretical literature on vertical integration, bandwagon behavior is deemed to occur when a firm integrates in response to vertical integration by rivals . In generic drug markets, firms make their entry and vertical integration decisions more or less simultaneously so that we do not observe firms choosing their vertical structures in response to the actions of their rivals. Nevertheless, bandwagon effects can still exist in the sense that firms may become vertically integrated in response to the expected prevalence of vertical integration among rivals. Such a possibility can be examined by seeing if the change in a firm’s payoff from becoming vertically integrated is increasing in the incidence or prevalence of vertical integration among rivals. In other words, we can check whether firms’ payoff functions exhibit strategic complementarity in vertical integration decisions. As Buehler and Schmutzler point out, vertical integration decisions are shown to be strategic substitutes rather than complements in most theoretical models. However, hydroponic rack there are a few important studies such as Ordover et al. , Hart and Tirole , and McLaren that demonstrate the possibility of strategic complementarity.

For instance, one US cement company’s annual report for 1963 mentioned that while it was not inclined to acquire assets in the ready-made concrete industry, the wave of vertical integration among its rivals was forcing the firm to follow suit. I now show, using a simple duopoly model, that when firms’ payoff functions are characterized by strategic complementarity in vertical integration decisions, the following testable prediction arises: a firm’s probability of vertical integration decreases with its rival’s cost of vertical integration. When vertical integration decisions are strategic substitutes, the opposite result holds: the firm’s vertical integration probability increases with the rival’s cost of vertical integration. These results allow us to design a simple econometric test of strategic complementarity. The prediction that vertical integration facilitates early API development during a patent challenge can be tested by seeing if ANDA applicants who make a paragraph IV certification are more likely than other applicants to be vertically integrated. However, my dataset only records whether or not each market is subject to one or more entrants making a paragraph IV certification. I therefore construct a market-level variable that indicates the occurrence of a paragraph IV patent challenge. This indicator variable essentially signifies a switch in the entry process: markets with no paragraph IV patent challenge are characterized by simultaneous entry, while paragraph IV markets are characterized by a race to be first. The empirical strategy is to see whether this switch in the entry process affects firms’ incentives to become vertically integrated. Using the market-level paragraph IV indicator variable as a determinant of firm-level behavior introduces a potential endogeneity problem: markets that are the subject of paragraph IV certification may be attractive to generic entrants in unobservable ways, and those unobserved factors may also influence entry and vertical integration decisions.

This endogeneity can be taken care of by modeling the process of paragraph IV certification, and allowing the error term in the firm-level equations and that in the paragraph IV equation to be correlated. Many authors note that paragraph IV patent challenges have become more common in recent years . Patent challenges may also be more likely in larger markets that offer greater profits to the first-to-file entrant during the exclusivity period. In addition, Grabowski and Hemphill and Sampat note that certain types of secondary patents – particularly those that cover formulations and new uses – tend to be more vulnerable to patent challenge, presumably because it is easier to invalidate or avoid infringing such patents. This suggests the following as possible market-level determinants of paragraph IV certification: market size, the number of originator patents of different types, and year dummy variables. The generic drug markets used for analysis are selected from a database of the US Food and Drug Administration , called the Orange Book, which contains the population of all drug approvals. I begin by selecting a subset of drug markets that opened up to generic competition between January 1, 1993 and December 31, 2005. The set of markets is further narrowed down to those where the relationship between the upstream and downstream segments is relatively straightforward. This is done by first restricting the downstream products to finished formulations containing only one API. When there are multiple single-ingredient formulations containing a given API, I choose only the first of these to open up to generic competition. This is based on the belief that when generic companies make their entry decisions in the first downstream market for a given API, the upstream market structure is not yet formed.

Therefore, it makes sense to view downstream and upstream entry decisions as being made simultaneously. By the time the other downstream markets using the same API open up, the upstream market structure may already be fixed. Because it is not realistic to assume that upstream and downstream actions are decided simultaneously in such markets, they are excluded from the analysis. I also restrict the sample to the following dosage forms which constitute the majority of generic drugs: oral solids, injectables, and topicals. This leaves 177 downstream markets, each defined by a distinct combination of an API and a dosage form. 128 markets remain after removing observations for which market characteristics data could not be obtained. There are 125 corresponding upstream markets, each defined by a distinct API. For three APIs , two different dosage forms went generic on the same day. In these cases, I consider different dosage forms of the same API to constitute independent markets, and combine each of them with data for their respective API markets. Thus, for the three APIs mentioned above, the same upstream market data are used twice. Table A.1 in the Appendix contains a list of the drugs in the sample. A processed version of the FDA data was obtained from a proprietary database called Newport Sourcing, developed and maintained by Thomson Reuters. Table 2.1 and Figure 2.1 presented in Section 2.2 are constructed from the dataset of 128 markets. The econometric model is estimated using observations on 85 of those markets that opened up to generic competition between 1999 and 2005. The reason for restricting the time period in this way is as follows. Between 1992 and 1998, the FDA did not grant 180-day generic exclusivity to the first-to-file paragraph IV applicant. Therefore, during this period generic firms had little incentive to develop their products early in order to engage in patent challenges. Thus, the paragraph IV status of a market is likely to have been irrelevant for the decision to vertically integrate. By limiting the sample to the post-1998 period, we can analyze the role of paragraph IV certification more accurately. To record the two firm-level outcomes – downstream entry and vertical integration – it is first necessary to pinpoint the date when each market opens up to generic competition. Previous authors such as Scott Morton define the market opening date as the approval date of the first ANDA. After comparing ANDA approval dates with the dates when the generic products actually began to be marketed, I find that this definition is not always appropriate. In some cases, vertical growing systems the first generic product is not marketed until several months after its ANDA is approved. During those months,subsequent generic products are not approved by the FDA. I also find a few cases where drugs that appear to be generics are marketed before their ANDAs are approved. The first phenomenon arises when pending patent litigation between the generic entrant and the originator firm, or a settlement between the two, prevent the generic from entering immediately upon ANDA approval. The latter phenomenon is related to a practice called “authorized generics”: the originator gives the generic company a license to sell the product based on the former’s New Drug Application rather than the latter’s ANDA. To accommodate these special cases, I define the market opening date as the first generic approval date or the first generic marketing date, whichever is later. Firm-level entry actions are defined on the basis of market opening dates. Specifically, a potential downstream entrant is considered to have entered the downstream segment if its ANDA is approved by the FDA either before the market opening date or not later than one year after the market opening date.

The relatively narrow window is justified on the grounds that entry timing is an important determinant of profits in generic drug markets; because prices fall rapidly in response to additional entry, most firms enter in the first few months after market opening . As for actions in the upstream segment, a downstream entrant is deemed to have vertically integrated if it submits a Drug Master File to the FDA before the market opening date or no later than one year after the market opening date. I identify a potential downstream entrant in market m as a firm who has entered the downstream segment of any other generic market, including one outside the sample, on a date that is earlier than market m’s opening date but that is no more than five years before that date. Thus, I allow a firm to remain a potential downstream entrant for five years after its last entry. Similarly, a firm is identified as a potential upstream entrant of market m if it has entered the upstream segment of another generic market prior to, but not more than seven years before, market m’s opening date. Therefore, potential entrant status in the upstream segment is allowed to last for seven years after the last entry event. The reason for setting a wider window for potential upstream entrants is that DMF submissions sometimes occur a few years before the market opening date. Firm i is a potential upstream-only entrant in market m if it is a potential upstream entrant but not a potential downstream entrant. To evaluate the potential entrant status of a given firm, it is necessary to accurately identify its previous entries. This requires correct names for the ANDA applicants and DMF holders contained in the FDA data. Similarly, identifying firms’ vertical integration actions, which involves matching the firms found in the downstream ANDA database with those in the upstream DMF database, requires accurate data on firm names. These tasks are complicated by the several mergers and acquisitions that took place in the generics industry during the observation period. As described in Appendix A.2, I use the Newport Sourcing database to attach accurate firm names to the FDA data. Changes in firm ownership are taken into account by assuming that the past entry experience of an acquired firm is fully carried over to the acquiring firm. Table 2.5 presents the distribution of actual entry actions taken by potential downstream entrants in the dataset. The data consist of 92 firms facing 2,539 choice situations spread across 85 markets. 406 of these choice situations result in downstream entry. 76 of the downstream entries lead further to vertical integration. Table 2.6 presents summary statistics for the covariates. The first fourteen variables are market characteristics. “User Population” is a measure of market size, which is expected to have a positive impact on a firm’s probability of downstream entry . However, its impact on a firm’s propensity to vertically integrate is an open question: while Stigler hypothesizes that vertical integration would occur less frequently in larger markets, others note that under certain conditions, the incidence of vertical integration may actually rise with market size. The user population variable is defined as the estimated number of users of each drug in the US during the period immediately before generic entry. It is constructed from results of the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey .

High runoff rates increase the mobility of contaminants from fields and decrease the HRT within the wetland, thus reducing the opportunity for filtering pathogens. Despite variations in several characteristics among the four flow-through wetlands in the case study described earlier, HRT was a consistently good predictor of E. coli removal efficiency. Mean removal efficiency was 69, 79, 82, and 95 percent for wetlands having mean HRTs of 0.9, 1.6, 2.5, and 11.6 days, respectively . Remarkably, an HRT of less than a day can allow for considerable E. coli retention , which means that a relatively small wetland area can treat runoff from a relatively large agricultural area. The relationship between removal and HRT was not so clear for enterococci . In this case, W-1, with an HRT of 2.5 days, demonstrated a lower removal rate than W-2 or W-3, which had HRTs of 0.9 and 1.6 days, respectively . These differences are clear evidence that different organisms can behave differently in wetlands. As discussed above, there are many parameters that can influence the environmental fate of pathogens in wetlands, including vegetation density, design, age, size, contributing area, and depth. The efficiency with which contaminants can be reduced in agricultural water as it passes through a wetland is largely dependent on the extent to which water is evenly distributed across the wetland area. A wetland’s retention capacity is diminished if its design results in stagnant zones that either reduce the effective treatment area or short-circuit longer flow paths, indoor growing trays decreasing the HRT. Efficient wetlands come in a variety of shapes and sizes.

A wetland should be wide enough to allow sufficient trapping of sediment and other particulate materials and long enough to permit sufficient residence time for nutrient removal. Most researchers agree that the surface area of a wetland should be as large as possible in order to maximize its HRT and storage capacity. The even dispersion of water across the wetland, termed hydraulic efficiency, is largely defined by the wetland’s dimensions and the relative locations of input and output channels. Designs with good hydraulic efficiency have a shape that facilitates complete mixing throughout the wetland without the persistence of stagnant zones, or may incorporate barriers that achieve the same effects . The sediment trap is an important design feature in settings where the input water has a high level of suspended solids . Sediment traps are essentially small swales or ponds positioned between the source of the agricultural water and the main wetland to promote the settling of coarse particles before the water is distributed across the wetland. Sediment traps should be located in easily accessible areas where sediment can conveniently be removed on a regular basis. Incorporation of sediment traps in your design will decrease the amount of sedimentation within the wetland, lengthening the time you can go between dredgings. They also prevent the burial of germinating seedlings in the wetland and help limit channelization and short circuiting of flow paths. The amount of microbial pollutants in wetland soils is significantly higher than in the standing water. Bacteria survive longer in soil than in water . Fecal coliforms can persist in sediments for as long as 6 weeks , so the degree to which sediments are deposited in a wetland has a significant effect on the degree to which bacteria are exported in effluent waters, post-wetland. The survival time for pathogens varies widely in agricultural settings, probably as a result of local differences in environmental conditions .

If conditions are conducive to pathogen survival, any of a number of wetland conditions that cause the re-suspension and entrainment of sediment—e.g., high water flow pulses into wetlands, wave action, or channelization—may lead to the release of waters that contain microbial pollutants. If you manage wetlands to allow for alternating episodes of flooding and drying, you may be able to decrease the survival of microbes in the wetland soil. In addition to desiccation associated with episodes of dry wetland soil, fluctuations in wetted surface area and depth can facilitate a diversity of biological and bio-geochemical conditions that optimize wetland function and minimize the duration of pathogen survival . There are two general options to reduce non-point source pollution from agriculture: on-site farm management practices that control the pollution source or limit the application of excess materials and their subsequent loss from farmlands, and off-site practices that intercept non-point source pollutants before they reach downstream waters. Wetlands can be used within a farm scape as either an on-site farm practice or an off-site tool, where downstream flood plains are converted to wetlands to mitigate pollution at the watershed scale. In settings where the attraction of wildlife is of concern, you may want to consider placing the wetland off-site, but at a place where it will intercept the runoff before it enters a natural water body. This may also require re-routing of the agricultural runoff into an off-site wetland.Since the work of Bain , the formation of market structure and its effect on market outcomes has been a central topic in industrial organization. In many industries, market structure is not only about the number of entrants and their respective market shares; there is also an important vertical aspect.

In particular, the role played by vertical integration – the combination of two or more vertically related functions within the same firm – has been a topic of active theoretical research. Authors have recognized the ability of vertical integration to influence market structure formation by deterring or facilitating entry. Vertical integration may also have a direct impact on market outcomes. For instance, two markets with similar horizontal market structures may have different price levels if the firms in one of them have a higher degree of integration into a vertically related activity. While many empirical studies have examined the relationship between vertical integration and market outcomes, with a few exceptions , vertical integration has not been treated explicitly as part of the market structure formation process. Meanwhile, the empirical entry literature has so far focused on horizontal interactions among firms; vertical interactions, including decisions to integrate, have not been explicitly incorporated into the econometric analysis of entry. The present dissertation fills this gap in the literature by combining the analysis of vertical integration with that of market entry. There are two benefits from doing so. First, the incorporation of vertical integration into the analysis of entry behavior lets us obtain a more accurate understanding of the market structure formation process. Second, utilizing an empirical framework based on market entry behavior allows us to investigate the motives for, and effects of, vertical integration in new and useful ways. The two empirical essays in this dissertation analyze market entry and vertical integration in the US generic pharmaceutical industry. Generic pharmaceuticals are drug products that become available to consumers after the expiration of patents and other market exclusivities that protect the original product. The industry provides a good setting for studying vertical market structure formation because it consists of many markets – one for each original drug – made up of two vertical segments. The upstream segment manufactures active pharmaceutical ingredients and the downstream segment processes APIs into finished formulations to sell to final consumers. In each market, multiple generic firms simultaneously choose their entry and vertical integration actions. Therefore, the industry provides a large number of market observations where vertical market structure formation takes place through the simultaneous and collective actions of individual firms. The first empirical essay, Chapter 2, seeks to explain the increased prevalence of vertically integrated entry in the generics industry since the late 1990s. Using a firm-level dataset covering 85 markets that opened up to generic competition between 1999 and 2005, I investigate the determinants of a generic firm’s decision to vertically integrate. I find that a firm has a higher probability of vertically integrating, mobile vertical grow racks conditional on its decision to enter the downstream segment, if it has greater past entry experience in the upstream API segment. This suggests that a firm’s upstream experience lowers its cost of vertical integration. I also find that a firm is more likely to vertically integrate when the average upstream experience among its rivals is higher. This effect can be divided into two parts. First, higher upstream experience among rivals implies a greater incidence of vertical integration in the equilibrium market structure. Second, the expectation of a more vertically integrated market structure raises the incentive for an individual firm to become vertically integrated. The latter effect suggests that vertical integration is characterized by bandwagon behavior. While bandwagon effects have been widely discussed in the theoretical literature, and anecdotal accounts of bandwagon behavior is not difficult to find, this result represents one of the first pieces of empirical evidence on its existence. The analysis also finds that generic firms are more likely to be vertically integrated in markets where they try to enter by filing a “paragraph IV certification” that challenges the patents held by originator pharmaceutical companies.

Generic entrants have an incentive to engage in such patent challenges, because the first-to-file paragraph IV entrant may be awarded a 180-day exclusivity in the generic market. I argue that in markets characterized by paragraph IV patent challenges, upstream investment into API development tends to be relationship-specific. This is because in such markets, the API has a much higher value if it is used by the first-to-file entrant than when it is used by some other firm. Such relationship specificity does not exist in other generic drug markets. Therefore, the higher relationship specificity of upstream investments in paragraph IV markets is likely to explain the higher incidence of vertical integration in such markets. Chapter 3 is another empirical essay. It specifies the formation of vertical market structure in generic drug markets as the outcome of a simultaneous-move vertical entry game. Firms choose their actions from a set containing up to four elements: unintegrated downstream entry, unintegrated upstream entry, vertically integrated entry, and no entry. The actions of rival firms enter the payoff functions of potential entrants so that vertical rival effects are measured. The estimated rival effects are then used to make inferences about the competitive effects of vertical integration. An econometric model of the vertical entry game is estimated using a dataset consisting of 85 markets that opened up during 1993-2005. Markets that are subject to paragraph IV patent challenges are not included in the analysis, because the entry process in such markets is characterized by a race to be first rather than a simultaneous-move game. The estimates suggest that vertical integration by rival entrants has a significantly positive impact on the payoffs of uninte-grated downstream entrants. This implies that vertical integration has strong efficiency effects that spill over to benefit unintegrated downstream firms. I also find that the profit of an unintegrated upstream entrant falls when, in a market structure consisting of two upstream firms and one downstream firm, the other firms become vertically integrated. This finding is also consistent with the existence of efficiency effects. The usefulness of the vertical entry model lies in its ability to accommodate policy simulations based on estimated parameters. In one such simulation, it is found that a policy that bans vertically integrated entry tends to decrease the number of downstream entrants in equilibrium. Combined with the finding that vertical integration has significant efficiency effects, this result supports the notion that vertically integration plays a procompetitive role in the generic drug industry.While vertical integration is a feature of many businesses, its incidence or prevalence varies across industries, across different markets in the same industry, and among firms operating in the same market. Explaining such variation in vertical integration has long been an active area of industrial organization research. The motives for vertical integration identified in the theoretical literature can be grouped into two major categories: improvement of efficiency for the integrating firm and foreclosure of rival firms from the supply of an input or from access to consumers. Each category is further divided into sub-categories. For instance, efficiency motives include the elimination of double margins, the facilitation of relationship-specific non-contractible investments, and the assurance of an input supply. In addition to these primary motives, a firm’s decision of whether or not to vertically integrate may be influenced by the actions of its rivals. For instance, a downstream firm’s incentive to integrate backward may be greater if a larger proportion of its rivals are vertically integrated. This would be the case if vertical integration has a foreclosure effect that raises the input price faced by the downstream firm. Thus, “bandwagon” behavior, where a firm vertically integrates in response to similar action by rivals, may be profitable under some circumstances.

Three phenomena can be observed from the baseline case AB results at different inlet mass flow rates: the flow above tray 4 always has a lower temperature than that above tray 3 since it is closest to the inlet region; at low inlet mass flow rate , the flow above tray 3 has the highest temperature due to buoyancy effect; and at high inlet mass flow rate , the flow above tray 1 has the highest temperature because it is located closest to the exit. The temperature distribution for case AD is very similar to that of the baseline case due to similar inlet/exit location orientations so that buoyancy is the dominant effect at low inlet mass flow rate . On the other hand, cases BC, BA, and DA have different temperature distributions than the baseline because the inlet and exit are located near the bottom and the top, respectively. Therefore, the temperature of tray 1 is much closer to the inlet temperature and the temperature increases with height except at high mass flow rate where the temperature above tray 4 can be lower than that above tray 3. This is due to strong helical flow mixing inside the room at high inlet mass flow rate, which also explains that the temperature uniformity increases with increasing inlet mass flow rate. Previous studies show that the optimal germination temperature is between 294 K and 297 K. As can be observed from Fig. 11, cases BC, BA, and DA at 0.3, 0.4, and 0.5 kg s−1, respectively, exhibit the desirable temperature range and distribution for lettuce growth. Nevertheless, compared to the baseline at each mass flow rate, case BC at an inlet mass flow rate of 0.3 kg s−1 exhibits the most significant average temperature reduction . Furthermore, indoor grow trays the average temperature of case BC at 0.3 kg s−1 is lower than that of the baseline case at 0.5 kg s−1, which demonstrates the design effectiveness of case BC.

Relative humidity represents the water vapor partial pressure in the IVFS, which has a strong effect on crop growth. It is reported that the ideal RH for lettuce and leafy greens should be between 50–70% . High RH can cause pathogen issues, like mildew and botrytis, and low RH can induce an outer leaf edge burn due to dryness. Therefore, the inlet RH is set to be 85% in this IVFS design. The comparison of RH for each tray between the highest OU and the baseline cases at different inlet mass flow rates is shown in Fig. 12. It can be observed from the baseline case that RH increases with increasing inlet mass flow rate due to the increase of water supply and decreasing room temperature. RH can be calculated from the ratio of the partial pressure of water vapor to the saturation vapor pressure at a given temperature. Therefore, RH can be increased by either increasing water partial pressure or decreasing temperature. In our study, temperature is the dominant parameter because the gas species composition in the system does not vary significantly. Therefore, the trend of RH distribution agrees with that of the temperature distribution in Fig. 11. The only exception exists for the baseline case AB when the inlet mass flow rate is the smallest . Under such conditions, tray 3 has higher temperature and RH than tray 4. To explain this behavior, the results from the CO2 distribution analysis need to be considered. At the lowest inlet flow rate, the flow has lowest circulation and tray 3 is near the end of the fresh inlet flow stream. Therefore, tray 3 has the lowest CO2 and highest H2O concentrations due to photosynthesis as shown in Figs. 10 and 12. Overall, the average RH distributions for cases BC and BA fall within the optimal range.Marijuana use has become increasingly normalized in the US and abroad. Since 1996, California has allowed marijuana for medical use.

An additional 17 states and the District of Columbia have followed suit by either allowing medical marijuana use or legalizing recreation use of marijuana. A trend among young people is smoking marijuana cigars . Marijuana cigars or blunts refer to cannabis rolled with a shell from an inexpensive cigar called a blunt, although any commonly available inexpensive small cigars or cigarillos are likely to be used . Blunt wrappers, which are tobacco leaf rolling papers that come in sealed packages, are also sold for rolling blunts. Due to the tobacco content in the wrapper leaf, smoking marijuana cigars may be considered as concurrent use of marijuana and tobacco. In this paper, we use the term “blunts” to talk about marijuana cigars and the term “blunt cigars” to talk about the inexpensive tobacco cigar that is typically used to make the marijuana cigars. Blunt cigars are cheap, frequently available at urban convenience stores, typically pre-cut with a blunt tip , and sold singly or in small packs of five. The present study examines factors associated with availability of tobacco products commonly used for blunts. Epidemiological surveys indicate that blunts are most commonly used by emerging adults , and that their use is generally increasing across all age groups. In 2005, 3.5% of all American youth aged 12–17 years were estimated to have used blunts in the past month , and a study among young adults aged 18-25 reported that between 2005 and 2008 past month blunts use ranged between 9% and 10.1% . By comparison, in 2011, 4.1% of youth aged 12–17 years, 11% of young adults aged 18-25years, 4.2% of adults aged 26-34 years and 1% of adults aged 35 or older reported using blunts in the past month , 2013. A recent study reported a moderate increase in the annual prevalence of blunt smoking among respondents aged 12-34 years old from 12% in 2004 to 14% in 2010 .

Other studies indicate that blunt smoking appears to be practiced among a growing number of racial/ethnic groups , such as Southeast Asian youth and young adults in California . Previous studies have found that, compared to other intake forms of marijuana, smoking blunts is more associated with male gender, low GPA, poor school attachment, not attending college, not working, and living in low income areas . Also, blunts smokers may have greater odds of being dependent on cannabis and tobacco and are at risk for smoking-related diseases . While tobacco remains the leading cause of preventable and premature death, killing an estimated 443,000 Americans each year , risks associated with marijuana use include impaired respiratory, cardiovascular and cognitive functioning and reduced mental health, as well as impaired driving ability and impaired function in school and at work . Blunts availability is likely to increase blunts use and problems associated with marijuana and tobacco use in local neighborhoods. Previous research suggests that exposure to and availability of drugs increase drug use and abuse . However, very little is known about availability of tobacco products associated with use of blunts. Studying the associations between neighborhood characteristics and availability of tobacco products used for blunts may help to identify areas at risk for blunts use and help policymakers and community advocates make better decisions about allocation of prevention resources. Analyzing 2000-2003 data from the National Survey on Drug Use and Health , Golub and colleagues showed that more than half of past-30-day marijuana users also reported current use of blunts. Among current blunts users, over two-thirds reported no current use of cigars, vertical grow racks for sale indicating blunts smokers may not define this practice as tobacco use. Similarly, a recent study suggested that young people recognize blunts as a form of marijuana use but do not recognize it as cigar use . Qualitative studies have also shown that youths may not consider blunts smoking to be a form of cigar use at all . These studies suggest the importance of studying the relationships between availability of tobacco products associated blunts use and societal-level influences related to normalization of marijuana use. Increased recognition of “recreational drug use” and increased support for legalizing some forms of marijuana use may contribute to normalization of marijuana and therefore to availability of products associated with blunts use. Societal-level influences related to normalization of marijuana use in the community may include rates of adult marijuana use. Recent studies have found that prevalence of adult drinking or smoking in the community are associated with increased underage drinking and youth cigarette smoking . These studies suggested that the level of adult drug use in the community reflect both community drug norms and availability. Medical marijuana policy and availability should also be considered as social influences related to normalization of marijuana. Our previous studies indicated that tobacco and alcohol policies were directly related to community norms . Although blunts smoking and use of other forms of marijuana may be seen as different practices , medical marijuana dispensaries might increase availability and ease of access to marijuana. Also, medical marijuana dispensaries may indirectly affect general acceptability of marijuana in the community.

The present study focuses on the associations between availability of tobacco products for blunts and social factors including neighborhood demographics, community-level marijuana use, medical marijuana policy and access to medical marijuana dispensaries and delivery services.This study used data from access surveys conducted at 1,000 tobacco outlets in 50 California cities with populations between 50,000 and 500,000. The sampling procedures for the 50 cities are described elsewhere in detail . This sample was a purposive geographic sample intended to maximize validity with regard to the geography and ecology of the state. Twenty randomly selected tobacco outlets in each city were surveyed. The sampling procedures for the tobacco outlets and survey procedures are also described in detail . In each city, data for the study were available for between 14 and 20 outlets . The selected tobacco outlets in each city were surveyed by two research assistants. At each outlet, a single research assistant attempted to purchase a pack of cigarettes and conducted a brief observation. After leaving the outlet, the research assistants recorded outlet data on a standardized form including whether blunt cigars, small cigars or cigarillos and blunt wrappers were for sale. Institutional review board approval was obtained prior to study implementation.Adult prevalence of past year marijuana use in each city was ascertained from 8,807 adults over the age of 18 years old who participated in a general population telephone survey conducted in the same 50 cities . Respondents were surveyed through a computer-assisted telephone interview. Listed addresses and telephone numbers obtained from various sources were used to develop a sample for the study. Listed samples of phone numbers is unbiased relative to random digit dialing techniques . Respondents were asked if they ever, even once, used marijuana or hashish. Respondents who had used marijuana or hashish were then asked about the number of days in the past 12 months they used marijuana or hashish. Those who reported never using marijuana or hashish or not doing so in the past 12 months were assigned a value of 0. All the others were assigned the value of 1. Adult prevalence of past year marijuana use was computed as the percent of past 12 month marijuana or hashish users in each city. Because of the skewed distribution, this variable was log10 transformed for analyses.Although California allows medical marijuana use, the state leaves regulations regarding the distribution of medical marijuana to patients up to local jurisdictions. Some localities have banned the distribution of marijuana through storefront dispensaries, have strict regulations on cultivation sites, have density restrictions on dispensaries, or some combination. Between June 2012 and July 2012, local city ordinances and policies around distribution and cultivation of marijuana were reviewed to determine whether the city permitted medical marijuana dispensaries or private cultivation in its jurisdiction. Cities were coded as allowing or not allowing medical marijuana storefront dispensaries and/or private cultivation within city boundaries.The density of medical marijuana dispensaries and delivery services is a measure of physical availability of medical marijuana in each of the 50 cities. Delivery services are an alternative means for users to obtain medical marijuana. These services can be available in any of the 50 cities, but are often more available in cities that do not allow distribution through dispensaries. Locations of storefront dispensaries and delivery service areas were obtained from seven different websites listing the information for these businesses in March – April 2012.