The weight of auxiliary evidence suggests, however, that this correlation primarily reflects factors other than a causal relationship of crime induction through intoxication. First, the psychopharmacological effects of marijuana are relatively modest compared to the effects of alcohol, cocaine, and other illegal drugs, and do not suggest, a priori, that intoxicated users are driven to violent, antisocial activity with great frequency. Second, it is clear from the sheer size of marijuana’s user base that most users do not resort to non-possessory crime at all—while intoxicated or otherwise. Third, some empirical evidence suggests that the enforcement of marijuana criminalization may not work even as a “broken windows” policing strategy,57 much less as a direct measure preventing supposedly toxicologically induced crime. A recent analysis of marijuana in public view arrests across 75 police precincts in New York City from 1989 to 2000 concluded that “there is no good evidence that this “reefer madness” policing strategy contributed to the decline in the sorts of serious crimes that are of greatest public concern in New York City” .On the contrary: while an initial panel data analysis offered some support for the idea that these misdemeanor marijuana arrests contributed to reductions in violent crime, when the authors restructured their regression model to control for mean reversion, the coefficient on MPV arrests became statistically significant in the opposite direction—suggesting that “an increase in MPV arrests over the period translates into an increase in serious crime—not,flood and drain tray as the broken windows theory would predict, a decrease in serious crime” . In considering the merits of criminalization, it is also important to remember that even within a system of criminalization, there is much leeway regarding the severity and nature of prohibition enforcement.
Moreover, there is significant historical and cross-country evidence to help understand how consumption and costs might change under a less punitive criminal regime. While it is always difficult to isolate the impact of a drug policy, and one must always be wary in generalizing from the experience of other countries to today’s America, there is evidence, albeit somewhat conflicting, suggesting that depenalization and even decriminalization of marijuana may not lead to significant increases in use. It is often said that in the 1970s, eleven states “decriminalized” marijuana . These states significantly reduced penalties for simple possession of marijuana, in some cases implementing a narrow form of the regime we call depenalization.On the other hand, a recent study finds that because other states have also reduced penalties for marijuana possession, “[so called] decriminalized states are not uniquely identifiable based on statutory law as has been presumed by researchers over the past twenty years” . The same study also finds, however, that the demand for marijuana among young people is sensitive to variation in penalties. A still more recent study traces the research—which began with studies finding little to no effect but now has become more mixed—and offers two possible explanations for the conflicting findings: the effect of legal variation is different across age groups; and the historical time period may matter . Moreover, the authors find that a reason for minimal effects of depenalization may be that many individuals are unaware of the changes in their state’s marijuana law.Another reason why use rates might not respond to decreased penalties is the extremely low likelihood of being arrested for illegal drug possession: reviewing the data, Boyum and Reuter estimate that in 1999, the “risk of being arrested for marijuana possession, conditional on using marijuana in the previous year, was about 3 percent; for cocaine the figure was 6 percent” .
To the extent that individuals predisposed to illegal drug use also exhibit lower risk aversion and higher discounting of future welfare than the rest of society, they are especially unlikely to find psychologically salient—or change their behavior as a result of— risks characterized by low probabilities and high costs, such as possible arrest for possession. Probably the most famous example of marijuana reform comes from the Netherlands. There, the 1976 “Opium Act” ushered in the de facto decriminalization of possession of small amounts of cannabis for personal consumption and a system of tolerated sale in “coffee shops” that in some sense resembles a form of highly but peculiarly regulated legalization. Under the latter system, registered coffee shop owners that adhere to certain guidelines may, without being targeted for prosecution, possess up to 500 grams of cannabis and sell it in quantities of 5 grams or fewer . The Dutch experience with this controlled form of drug use provides insight into what could happen if the United States were to move down a path toward depenalization, decriminalization, or even legalization of marijuana. MacCoun and Reuter report that since the 1976 reform, the number of “coffee shops” has increased steadily so that there now may be between 1200 and 1500 such venues in Amsterdam; on the other hand, van der Gouwe, Ehrlich, and van Laar report a decrease in the number of officially tolerated coffee shops from 1999 to 2007. Marijuana use in the Netherlands increased during the 1980s and early 1990s as the “coffee shops” became more widespread. However, there is no evidence for the existence of the so-called “gateway effect” discussed earlier. Notably, there was no increase in use rates of heroin, which is traditionally the most widely used hard drug in the Netherlands, or of cocaine, in spite of the corresponding crack crisis in the United States . Indeed, the European School Survey Project on Alcohol and Other Drugs conducted a quarter-century after de facto decriminalization and emergence of the coffee shop system in the Netherlands found that only 28 percent of Dutch school children surveyed reported smoking cannabis compared with 38 percent in France, whose politicians have been harshly critical of the Dutch approach.Also, as we note in Figure 1 below, data from the World Health Organization World Mental Health Surveys indicate that when measured in terms of lifetime cannabis use, the United States has a much higher rate of those over age 18 who have ever used cannabis compared with the Netherlands .
One of the goals of the Dutch scheme involves separating cannabis sales from sales of other illicit drugs in the hopes that cannabis users will not come into contact with sellers of drugs like heroin, thus stopping marijuana users from moving to more serious drugs. Manja Abraham reported that for users over age 18, 48 percent of cannabis purchases took place in coffee shops, whereas relatives and friends supplied 39 percent of cannabis used . While this demonstrates that a large informal cannabis market exists, only 3.7 percent of users reported obtaining cannabis from a stranger and 5 percent from a home dealer, someone who advertises cannabis sales and delivers them to the home, legally or illegally, depending upon the amount delivered. Among experienced users of cannabis , 54 percent reported purchasing cannabis most often in a coffee shop compared with 32 percent for less-experienced users . This suggests that while a large percentage of sales occur outside of the state-sanctioned coffee shops, the heaviest users obtain their cannabis through regulated channels or from people they know, rather than participating in a clandestine market of dealers. The lack of transactions with dealers who are otherwise unrelated to the individual is important because it is such transactions that bring an individual into contact with the black market and its associated crime and violence. Evidence from Portugal and Australia also suggests that depenalization need not lead to substantial increases in marijuana use or its associated problems. In the period since decriminalization,hydroponic tables canada drug use in Portugal has not spiked, nor has the country been besieged by drug tourists . In fact, Portugal continues to have among the lowest rates of cannabis and cocaine use in the European Union, and its rates remain far below their counterparts in the United States . Room et al. have pulled together a handful of studies comparing changes in use rates in Australian jurisdictions covered by schemes involving civil penalties for small cannabis offenses with changes in use rates for the rest of Australia still subject to the country’s standard criminal penalties for marijuana possession. On the whole, these analyses offer little if any evidence to suggest that use rates increased more in civil penalty jurisdictions than elsewhere. In the United States, medical marijuana laws have begun to create a subsystem that, under our taxonomy, would be considered a form of decriminalization verging on a highly regulated form of legalization. Medical marijuana laws have introduced a mechanism that allows patients to grow and use marijuana for medical purposes without facing the prospect of state prosecution, while still allowing the states and the federal government to continue prohibiting the large-scale cultivation, distribution, and ordinary possession of marijuana. Fifteen U.S. states have provisions allowing for some type of medical marijuana; however, these subsystems of decriminalization differ from state to state.
For example, in Colorado, a constitutional amendment providing for medical marijuana included the requirement that patients using medical marijuana possess a registry identification card issued by the state, and it provided for the establishment of a confidential state registry for this purpose.In California, probably the best-known example of a medical marijuana regime in the United States, the Compassionate Use Act of 1996 simply declares as one of its purposes: “to ensure that patients and their primary caregivers who obtain and use marijuana for medical purposes upon the recommendation of a physician are not subject to criminal prosecution or sanction.”This act did not create a mandatory registry program for patients using medical marijuana. Rather, in 2004, California introduced a voluntary Medical Marijuana ID card, administered by the county governments.While California’s medical marijuana dispensaries have been the focus of several news stories since the Obama Administration announced that agencies in charge of enforcing federal drug laws would no longer raid such dispensaries , the legal status of dispensaries remains questionable, and it would be misleading simply to say that California legalized the “sale” of medical marijuana . The Compassionate Use Act did not provide for sales through such dispensaries, and the expanded codification of medical marijuana in California occurring in 2003 provided only for multiparty growing of marijuana in collectives and cooperatives.California’s Attorney General has indicated that for dispensaries to operate legally in California, they must operate as a non-profit, only sell to members of the collective, verify members’ status as qualified patients or primary caregivers, only acquire marijuana from qualified members, and only cultivate and transport amounts required to meet the needs of the collective’s members . The California courts have also placed limits on the ability of individuals cultivating and selling marijuana to avoid prosecution for possession and sale of the drug by claiming to be the “primary caregiver” of multiple patients. The California Supreme Court has held that a patient’s primary caregiver must establish such status “based on evidence independent of the administration of medical marijuana,” and that growth and supply of medical marijuana alone are insufficient to establish oneself as a primary caregiver. The California Supreme Court has also held that employers can fire medical marijuana patients who test positive for marijuana as a result of a urinalysis, because the drug remains illegal at the federal level, and nothing prevents employers from terminating employees who use illegal substances.Thus, while medical marijuana states like California have decriminalized marijuana possession and use for medical marijuana patients, users still face repercussions such as loss of employment and certain limitations on purchases of marijuana that would presumably be reduced or eliminated in a legalization regime. From a cost-minimization perspective, the primary expected benefits of legalization over depenalization would be even more substantial reductions in government expenditures on drug control, new tax revenues to offset remaining government spending, the potential for increased government control over product standards and labeling information, and substantial reductions in drug-related crime costs. Government regulation of labeling and product standards could help mitigate the problems of increased potency and user uncertainty regarding whether the drug taken has been laced with, or partly replaced by, other harmful ingredients the consumer did not intend to use—such as PCP. As noted earlier, Miron estimates that the tax revenues from legalized marijuana would indeed be substantial—somewhere between $2.4 and $6.2 billion.