This paper sheds light on previous inconsistencies identified in the literature regarding the relationship between medical marijuana laws (MMLs) and recreational marijuana use by closely examining the importance of policy dimensions (registration requirements, home cultivation, dispensaries) and the timing of when particular policy dimensions are enacted. Using data from our own legal analysis of state MMLs, we evaluate which features are associated with adult and youth recreational and heavy use by linking these policy variables to data from the Treatment Episodes Data System (TEDS) and the National Longitudinal Survey of Youth (NLSY97). We employ differences-in-differences techniques, controlling for state and year fixed effects, allowing us to exploit within-state policy changes. We find that while simple dichotomous indicators of MML laws are not positively associated with marijuana use or abuse, such measures hide the positive influence legal dispensaries have on adult and youth use, particularly heavy use. Sensitivity analyses that help address issues of policy endogeneity and actual implementation of dispensaries support our main conclusion that not all MML laws are the same. Dimensions of these policies, in particular legal protection of dispensaries, can lead to greater recreational marijuana use and abuse among adults and those under the legal age of 21 relative to medical marijuana laws without this supply source.

This paper sheds light on previous inconsistencies identified in the literature regarding the relationship between medical marijuana laws (MML) and recreational marijuana use by closely examining the importance of policy dimensions (registration requirements, home cultivation, dispensaries) and the timing of them. Using data from our own legal analysis of state MMLs, we evaluate which features are associated with adult and youth recreational use by linking these policy variables to data from the National Longitudinal Survey of Youth (NLSY97), the Youth Risk Behavior Survey (YRBS) and the Treatment Episodes Data System (TEDS). Our analyses control for state and year fixed effects, using within state policy changes over time to estimate the effect on changes in our outcome variables using a difference-indifferences approach. We find that while simple dichotomous indicators are generally not associated with marijuana use, specific dimensions of MMLs, namely home cultivation and legal dispensaries, are positively associated with marijuana use in each data set. Moreover, these same dimensions are tied to binge drinking and fatal alcohol automobile accidents as well. The findings have important implications for states considering legalization of marijuana, as regulating access to and promotion of dispensaries may be key for reducing the harms associated with these policies.

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Background Marijuana potency has risen dramatically over the past two decades. In the United States, it is unclear whether state medical marijuana policies have contributed to this increase. Methods Employing a differences-in-differences model within a mediation framework, we analyzed data on n = 39,157 marijuana samples seized by law enforcement in 51 U.S. jurisdictions between 1990-2010, producing estimates of the direct and indirect effects of state medical marijuana laws on potency, as measured by Δ9-tetrahydrocannabinol content. Results We found evidence that potency increased by a half percentage point on average after legalization of medical marijuana, although this result was not significant. When we examined specific medical marijuana supply provisions, results suggest that legal allowances for retail dispensaries had the strongest influence, significantly increasing potency by about one percentage point on average. Our mediation analyses examining the mechanisms through which medical marijuana laws influence potency found no evidence of direct regulatory impact. Rather, the results suggest that the impact of these laws occurs predominantly through a compositional shift in the share of the market captured by high-potency sinsemilla. Conclusion Our findings have important implications for policymakers and those in the scientific community trying to understand the extent to which greater availability of higher potency marijuana increases the risk of negative public health outcomes, such as drugged driving and drug-induced psychoses. Future work should reconsider the impact of medical marijuana laws on health outcomes in light of dramatic and ongoing shifts in both marijuana potency and the medical marijuana policy environment.

we assess the seriousness of incarcerated drug offenders along dimensions of dangerousness, culpability, and harm-specifically, functional role and drug group participation, type and amount of drugs, firearms involvement, and criminal conviction and arrest history. We find that only about 1.6% of federal and 5.7% of state inmates can be described as "unambiguously low-level. " Alternatively, not many are "kingpins." Rather, most fall into a middle spectrum representing different degrees of seriousness that depend on what factors are emphasized. Policy Implications:Our findings dampen hopes of dramatically reducing prison populations by getting out of prison those who are unambiguously low-level drug offenders. They simply do not represent the majority of incarcerated drug offenders. I n particular, most played some role in distribution, so eliminating prison terms for users (decriminalization) would not have affected many now in prison. Indeed, if decriminalization increased demand, it could plausibly increase prison populations by increasing the number of suppliers still subject to imprisonment. On the other hand, "drug courier exceptions" to sentencing laws that apply to minor role offenders possessing large quantities could have a greater prison reduction impact.