Do Medical-Marijuana Laws Reduce Highway Deaths?
By Christopher Shea blogs.wsj.com
Medical-marijuana laws reduce traffic deaths, according to a new study, probably because people in states with such laws partly substitute marijuana for alcohol — and alcohol is more deadly when combined with driving.
Fifteen states plus the District of Columbia have passed medical-marijuana laws since 1996. Examining National Highway Traffic Safety Administration data before and after the passage of those laws, the researchers found a nearly 9% decrease in overall traffic fatalities. (The calculations also took account of trends in neighboring states.) That decline was caused entirely, or nearly so, by a drop in alcohol related traffic deaths.
In states that have legalized medical marijuana, the researchers found evidence of an increase in marijuana consumption—beyond prescription uses — among people over 18 (but not under 18).* According to their analysis of data collected by the Centers of Disease Control and the states, those states have also seen a slight drop in alcohol consumption. Taken as a whole, the data suggest that marijuana is being used as a partial replacement for drinking, and not only a supplement to drinking.
Like alcohol, marijuana hinders physical coordination. People who are high, however, tend to be more aware of their intoxication, and less aggressive and reckless, than people who are drunk, the researchers said. Another factor in the fatality drop may be that people consume marijuana in private, rather than in bars (or sports stadiums) they drive home from.
Source: “Medical Marijuana Laws, Traffic Fatalities, and Alcohol Consumption,” D. Mark Anderson and Daniel I. Rees, Institute for the Study of Labor working paper (November)
*That medical-marijuana laws lead to more marijuana use among adults was the general trend, but it wasn’t universal. Montana, where nearly 3% of the population has a marijuana prescription (!), and Rhode Island, where only some 3,000 people do, both saw increases in pot consumption. Vermont, however, with a medical-marijuana patient roster measured in the hundreds, did not see an increase in pot consumption.