Impacts of medical marijuana legalization on arrest rates for adults and juveniles

Background:

Medical marijuana legalization (MML) is often thought to increase crime as dispensaries and homes known to cultivate marijuana represent prime targets for burglary or robbery.  This study examines the effect of MML on arrest rates for various crimes, and whether these effects differ by age group.

Method:

Using state-level data from the 1994-2012 Uniform Crime Reports, this study estimates linear regression models using a difference-in-difference identification strategy to estimate the effect of MML on arrest rates for a series of property, violent, and non-violent crimes while controlling for state demographic and economic characteristics. Models are estimated for adults (aged 18 and over) and juveniles (under 18) to identify potential heterogeneous effects of MML across age groups.  Models also control for in-home cultivation of medical marijuana and the presence of dispensaries in each state.

Results:

Preliminary estimates indicate that MML significantly decreases drug abuse violation arrests for the entire population.  However, this decrease is largely driven by adults, as drug abuse violations decline by over 11 percent for this group. Initial results also suggest that MML significantly decreases juvenile arrests for income-generating crimes, such as burglary and theft, which each decrease by approximately 10 percent. 

Conclusions:

The U.S. experience with medical marijuana illustrates a linkage between health and criminal justice policy.  While further research is required to understand the mechanism linking arrest rates and medical marijuana legalization, this study demonstrates the potential role for public health policy to impact policy goals related to crime.