The implications of marijuana decriminalization and legalization on crime in the United States (2017)

Through 2014 Uniform Crime Report (UCR) data for all 50 U.S. states, this research explores the relationship between decriminalization and recreational and medical marijuana legalization and crime rates and arrests for drug abuse violations. When comparing states that changed their marijuana laws between 2010 and 2014 to states without any change, results indicate that any decrease in crime rate was not dependent upon changes in laws. Results indicate that while the trend is for property and violent crime rates to be higher in states where marijuana remains illegal, the difference is not statistically significant. When comparing states where marijuana has been decriminalized and states where medical marijuana has been legalized to states where it has not, the trend is that property and violent crime rates appear to be lower in both decriminalized and medically legalized states, but the difference is not statistically significant. Analysis also reveals that there are no significant differences in 2014 crime rates based on the degree to which the state has legalized/decriminalized marijuana (completely illegal, decriminalized or medically legal, decriminalized and medically legal). Even when controlling for factors that may lead to crime, the legal status of marijuana in states failed to significantly predict property or violent crime rates in 2014. States may turn to this research when considering their marijuana laws.