The effects of recreational marijuana laws on drug use and crime

Recreational marijuana laws (RMLs), which legalize the sale and possession of small quantities of marijuana for recreational use, have been adopted by 24 states and the District of Columbia. Using a generalized difference-in-differences approach and data for the period 2000–2019 from a variety of sources (the National Survey of Drug Use and Health, the Uniform Crime Reports, the Treatment Episode Data Set, and the National Vital Statistics Mortality files), this study comprehensively examines the effects of legalizing recreational marijuana on drug use, crime, and admissions to substance use treatment facilities. Our analyses show that RML adoption increases the use of marijuana by adults and reduces marijuana-related arrests. However, we find little evidence that RMLs increase the use of harder drugs, admissions to substance use treatment facilities, or property and violent crime. In fact, our results are consistent with the hypothesis that marijuana and opioids are substitutes.