Do Medical Marijuana Laws Increase Hard-Drug Use?

Medical marijuana laws generate significant debate regarding drug policy. For instance, if marijuana is a complement to hard drugs, then these laws would increase the usage not only of marijuana but also of hard drugs. In this paper I study empirically the effects of medical marijuana laws by analyzing data on drug arrests and treatment admissions. I find that medical marijuana laws increase these proxies for marijuana consumption by around 10-15 percent. However, there is no evidence that cocaine and heroin usage increases. From the arrest data, the estimates indicate a 0-15 percent decrease in possession arrests for cocaine and heroin combined. From the treatment data, the estimates show a 20 percent decrease in admissions for heroin-related treatment, although there is no significant effect for cocaine-related treatment. These results suggest that marijuana may be a substitute for heroin, but it is not strongly correlated with cocaine. I believe marijuana should be illegal in our country. It is the pathway to drug usage by our society, which is a great scourge-which is one of the great causes of crime in our cities. (Mitt Romney, October 4, 2007 [Altieri 2012]) I believe that marijuana is a gateway drug. (John McCain, August 11, 2007 [Zaitchik 2008]) [ABSTRACT FROM AUTHOR]