Association for Public Policy Analysis & Management

Over the past decade, state laws regulating the sale and possession of marijuana have undergone significant changes.  To date 21 states have legalized some form of medical marijuana use for adults and two states have legalized the recreational use of the drug.  While the policies have engendered significant public debate, relatively little is known about their effects from an economic perspective.  In this paper we will use data from the Youth Risk Behavior Survey (YRBS) from 1995 to 2011 to study the impact of several marijuana legalization policies on youth marijuana use, alcohol consumption, other drug use, and cigarette smoking. The analysis data contains a representative sample of over 800,000 high school youth from 39 states.  In addition, we will also estimate the association between these risky behaviors and youth academic performance (grades).  The marijuana legalization policies that we will model include: medical marijuana legalization, youth medical marijuana legalization, legal possession limits, and restrictions on the site of use, among others.  Our models will control for potential policy endogeneity using standard instrumental variables methods. We find that MMLs have the effect of increasing the probability that youth ever try marijuana and decrease student grade point averages, though we find little evidence of a “gateway” effect for other drugs.  Finally, we will discuss the magnitude of the measured spillover effects on risky behaviors and school attainment relative other similarly-debated policies.