Comparative Effects of Recreational and Medical Marijuana Laws On Drug Use Among Adults and Adolescents

Abstract

Thirty-four states have adopted medical marijuana laws and ten states have adopted recreational marijuana laws. There is little research comparing how these two types of laws affect drug consumption. Using a difference in difference strategy, we find that recreational laws increase past-year marijuana use by 25% among adults and by 10% among adolescents. In contrast, medical laws increase adult use by only 5% and have a negligible effect on adolescent use. We also find that recreational marijuana dispensaries are an important driver of the increase in marijuana use for adults 26 and over. Taken together, our results suggest that medical laws are not de facto recreational laws in that they succeed in mitigating recreational use and that recreational laws have much broader effects on overall levels of marijuana use. The results also raise concerns that underage marijuana use may be an important problem with existing implementations of recreational marijuana laws.

Keywords: marijuana use, recreational marijuana, medical marijuana, substance abuse, adolescent drug use

JEL Classification: I18, I10, K32