Relationship between Legal Access to Medical and Recreational Marijuana and Motor Vehicle Fatalities in the US

Abstract

There exists some economic literature regarding the legalization of alcohol and cigarettes, and the relationship of each to motor vehicle accidents. Yet, there are only a few that have studied the legalization of marijuana laws in recent years. In 1996, California became the first state to legalize marijuana for medical purposes. In 2012, Colorado Amendment 64 legalized the sale and possession of marijuana for non-medical uses. Since then more states have enacted similar laws allowing citizens to consume marijuana for medical and/or recreational purposes. As of October 2017, 29 states and the District of Columbia have statewide medical marijuana laws. Additionally, 8 states and D.C. have legalized recreational use of marijuana. This paper focuses on the effects of policy changes that legalize medical and recreational marijuana use on motor vehicle accidents. I used data from Fatality Analysis Reporting System (FARS) from the US Department of Transportation to observe the changes of the numbers of motor vehicle accidents. Specifically, I used difference-in-differences model to determine if there is evidence that legalization of medical and recreational marijuana has effects on motor vehicle accidents fatalities. The preliminary results show that the legalization of medical marijuana laws are associate with a decrease in traffic fatalities by 5.8 percent, while the legalization of medical recreational laws are associate with a decrease in traffic fatalities by 6.3 percent. In addition, I will study the change in numbers of alcohol related traffic fatalities before and after the legalization laws.