Marijuana Moment is a wire service assembled by Tom Angell, a marijuana legalization activist and journalist covering marijuana reform nationwide. The views expressed by Angell or Marijuana Moment are neither endorsed by the Globe nor do they reflect the Globe’s views on any subject area.
One concern that marijuana legalization opponents often voice is the fear that dispensaries will increase local criminal activity. But a new study found the opposite to be true.
“The results imply that an additional dispensary in a neighborhood leads to a reduction of 17 crimes per month per 10,000 residents, which corresponds to roughly a 19 percent decline relative to the average crime rate over the sample period,” the paper states.
The study, published last week in Regional Science and Urban Economics, is one of the first to look at how legalization affects neighborhood crime rates in the short-term.
Researchers used local monthly crime-related data in Denver — where legal adult-use cannabis sales began in January 2014 — over the span of January 2013 to December 2016.
As the researchers write, “The City of Denver is the clear mecca of recreational marijuana sales in Colorado.” They also mapped out the location of recreational and medical dispensaries that opened and closed during the study period, finding that dispensaries were more often located in neighborhoods with higher poverty, more minorities, and a higher number of jobs for the number of people who live there.
Although crime in nearby counties fell by 0.2 percent between 2013 and 2014, crime rates in Denver itself increased by 1.7 percent — except in neighborhoods that gained dispensaries.
“We find that adding a dispensary to a neighborhood (of 10,000 residents) decreases changes in crime by 19 percent relative to the average monthly crime rate in a census tract,” the study’s authors write. “These results are robust to many alternative specifications, are unique to time periods after legalization, and diminish quickly over space.”
“Our results are consistent with theories that predict that marijuana legalization will displace illicit criminal organizations and decrease crime through changes in security behaviors or substitution toward more harmful substances.”
Although the study found that the anti-crime effects of marijuana retail operations are “highly localized, with no evidence of spillover benefits to adjacent neighborhoods,” the authors suggested it is reasonable to infer that the reductions in crime associated with nearby dispensaries add up to city-wide benefits.
“If it is the case that municipal-level changes in crime are an aggregation of neighborhood effects on crime, then our research would suggest that the legalization of legal marijuana markets would decrease crime at the municipal level,” they wrote.
As for the nature of the crimes deterred by legal access to marijuana, researchers found that a majority of the criminal offenses that decreased were nonviolent. They included criminal trespassing, public disorder, criminal mischief, and simple assault.
The study also found that drug-related offenses fell by 2.3 crimes per month for a neighborhood of 10,000 residents: There was no change in the number of cannabis-related crimes after a local dispensary opened, but there were small declines in the number of offenses related to methamphetamine, cocaine, and heroin. It’s possible, the authors note, that the increased presence of law enforcement near dispensaries helps deter some of these offenses.
“The results show no evidence supporting theories that marijuana dispensaries increase local cannabis crimes (since we do not find increases in marijuana crimes such as cultivation, possession, or sales nearby) or that dispensaries increase crimes through increased intoxication (since there is essentially no change in the number of crimes with marijuana as a ‘contributing factor’ near locations that gain dispensaries),” the study concluded.
“These findings are consistent with previous research that has found no link between marijuana use and criminal behavior.”
A separate 2017 study found that retail shops dedicated to the sale of alcohol and tobacco products attracted more criminal activity than medical marijuana dispensaries.