Maerker: In Mexico, there are those who propose not keeping going with this battle and legalize drug trafficking and consumption. What is your opinion?
Clinton: I don't think that will work. I mean, I hear the same debate. I hear it in my country. It is not likely to work. There is just too much money in it, and I don't think that--you can legalize small amounts for possession, but those who are making so much money selling, they have to be stopped.
This is from an interview of then Secretary of State Hillary Clinton in early 2011. It's quoted by Jacob Sullum of Reason. Denise Maerker of Televisa had asked Clinton's opinion of proposals to reduce black-market violence by repealing drug prohibition.
As Jacob wrote at the time:
Clinton evidently does not understand that there is so much money to be made by selling illegal drugs precisely because they are illegal. Prohibition not only enables traffickers to earn a "risk premium" that makes drug prices much higher than they would otherwise be; it delivers this highly lucrative business into the hands of criminals who, having no legal recourse, resolve disputes by spilling blood. The 35,000 or so prohibition-related deaths that Mexico has seen since President Felipe Calderon began a crackdown on drugs in 2006 are one consequence of the volatile situation created by the government's arbitrary dictates regarding psychoactive substances. Pace Clinton, the way to "stop" the violent thugs who profit from prohibition is not to mindlessly maintain the policy that enriches them.
So what have been the results of deregulation of medical marijuana in the United States?
We show that the introduction of medical marijuana laws (MMLs) leads to a decrease in violent crime in states that border Mexico. The reduction in crime is strongest for counties close to the border (less than 350 kilometres) and for crimes that relate to drug trafficking. In addition, we find that MMLs in inland states lead to a reduction in crime in the nearest border state. Our results are consistent with the theory that decriminalisation of the production and distribution of marijuana leads to a reduction in violent crime in markets that are traditionally controlled by Mexican drug trafficking organisations.
This result should not be surprising and, I'm willing to bet, didn't surprise the authors. Because the above Economic Journal article is gated, I went to the 2014 ungated version here.
Here's their explanation:
We argue that the main difference between states with and without MML is not the availability of marijuana. Many studies show that marijuana is widely available in states without MML in place (e.g. National Drug Threat Assessment Report NDIC, 2011, Kilmer et al., 2014). Moreover, a large number of states have decriminalized the use of marijuana in policies dating back to the 1970's. Instead the main difference between states with and without MML lies in the origin of the drug. Traditionally, marijuana markets have been firmly in the hands of Mexican DTOs. However, since their introduction MML create legitimate competition to DTOs by increasing the local production of marijuana within the US.
There is a large amount of anecdotal evidence that suggests MML have indeed provided Mexican DTOs with strong competition from within the US. According to the 2011 National Drug Threat Assessment Report (NDIC, 2011), US production has increased more than twofold in the period 2005-2009, coinciding with the introduction of MML in many states. In addition, price data indicates that the quality-adjusted price of marijuana has decreased by 6 percent in the period 2009-2012 alone (UNODC, 2014). In the background section we present self collected data on the number of marijuana dispensaries in MML states, which shows that makeup of medical marijuana indeed appears to be substantial. Several articles in popular media also suggest that the increase in production that results from MML and the later legalization of marijuana in Colorado and Washington negatively affected the activity of Mexican DTOs (e.g. articles from the Washington and Huffington Post Khazan, 2012, Miroff, 2014, Knafo, 2014.)