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Thursday, December 8, 2011

Medical marijuana for the win

Sixteen states have now passed medical marijuana laws (MML), allowing physicians to prescribe marijuana to patients who can either grow it themselves or obtain it from legal growers.  Have there been any unforeseen consequences of this change?  According to a preliminary report by Mark Anderson of Montana State University and Daniel Rees from the University of Colorado, Denver, legalizing marijuana may be significantly reducing traffic fatalities.

Traffic fatalities (as reported by the Fatality Analysis Reporting System) decreased by 9% after the implementation of MMLs.  Why should this be so?  After all, marijuana does have detrimental affects on one’s ability to drive.  Distance perception, hand-eye coordination and reaction time are all adversely affected by marijuana usage, just as they are by alcohol consumption.

For one thing, unlike drunk drivers, who tend to speed and take risks, stoned drivers tend to compensate for their defect by driving more slowly and carefully.  Therefore, using marijuana rather than alcohol would be of benefit to motorists (though obviously, using neither would be preferable--using cannabis is also associated with car crashes).  Data from the Beer Institute confirm that beer sales do fall upon the passage of MMLs, suggesting that some people switch from alcohol to marijuana when the latter is available.

Perhaps even more significantly, because people can legally drink in public places, they often find themselves in need of transportation home, which they may unwisely provide for themselves.  The often problematic legal nature of medical marijuana ensures that it is primarily used in the home.

By the way, a 9% decrease in traffic fatalities is nothing to sneeze at.  This is about the same savings in lives achieved by mandatory seat belt laws.  It does make one wonder what would happen if all marijuana usage were decriminalized.