By Edward M. Shepard and Paul R. Blackley. Journal of Drug Issues.
State medical marijuana programs have proliferated in the United States in recent years. Marijuana sales are now estimated in billions of dollars per year with over two million patients, yet it remains unlawful under Federal law, and there is limited and conflicting evidence about potential effects on society. We present new evidence about potential effects on crime by estimating an economic crime model following the general approach developed by Becker. Data from 11 states in the Western United States are used to estimate the model and test hypotheses about potential effects on rates of violent and property crime. Fixed effects methods are applied to control for state-specific factors, with adjustments for first-order autocorrelation and cross-section heteroskedasticity. There is no evidence of negative spillover effects from medical marijuana laws (MMLs) on violent or property crime. Instead, we find significant drops in rates of violent crime associated with state MMLs.