A new study completed by Daniel Rees, an economics professor at the University of Colorado Denver, and D. Mark Anderson, at Montana State University, reveals that states that have legalized medical marijuana have seen traffic deaths drop by nine percent, while beer sales were reduced five percent.
"We were astounded by how little is known about the effects of legalizing medical marijuana," says Rees in a statement. "We looked into traffic fatalities because there is good data, and the data allow us to test whether alcohol was a factor."
The study analyzed traffic-related deaths nationwide, including the areas supporting MMJ, between 1990 and 2009. In the medical cannabis states, the pair found statistics that show alcohol consumption by 20- to 29-year-olds went down.
The economists noted that simulator studies conducted by previous researchers suggest that drivers under the influence of alcohol tend to underestimate how badly their skills are impaired. They drive faster and take more risks. In contrast, these studies show that drivers under the influence of marijuana tend to avoid risks. However, Rees and Anderson cautioned that legalization of medical marijuana may result in fewer traffic deaths because it's typically used in private, while alcohol is often consumed at bars and restaurants.
"I think this is a very timely study given all the medical marijuana laws being passed or under consideration," Anderson says. "These policies have not been research-based thus far and our research shows some of the social effects of these laws. Our results suggest a direct link between marijuana and alcohol consumption."
The study also examined marijuana use in three states that legalized medical marijuana in the mid-2000s, Montana, Rhode Island, and Vermont. Marijuana use by adults increased after legalization in Montana and Rhode Island, but not in Vermont. There was no evidence that marijuana use by minors increased.
Look for our interview with Rees in Thursday's Independent.