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Think Tanked
Posted at 11:45 AM ET, 10/13/2011

RAND pulls study on medical marijuana dispensaries

The RAND Corporation has removed a study from its website that claimed crime increased near medical marijuana dispensaries in Los Angeles after they closed because of a city ordinance issued last year.

RAND says the study has been pulled from the website while it undergoes additional internal review and will be reissued the upon completion of the review, but declined to say what the specific areas of concern are. The think tank also plans to continue the research to make broader conclusions about crime and medical marijuana.

However, one of the chief faults of the immediate study appears to be in the data collection. Locations that had been tallied as closed remain open and areas credited with having shops, such as Beverly Hills, never had them.

The study also suffers from a short duration of data collection, a weakness RAND recognized in the press release. The study collected crime reports in the ten days immediately before and immediately after the supposed closing of the dispensaries--a time frame many social scientists would say couldn’t possibly capture enough data to spot crime trends.

In addition, RAND was aware of the study’s shortcomings and noted them in the original press release (full text after the jump):

Researchers say their findings should be interpreted cautiously, given that they studied a relatively short period of time and that the margin of error was high.

The study was financially supported by the Robert Wood Johnson Foundation’s Public Health Law Research program. The foundation has sponsored research in the past on the use of medical marijuana.

Full text of the study’s press release after the jump.

The full text of the press release for the report at the time of publication:

When medical marijuana dispensaries close, crime rises in the surrounding neighborhood when compared to areas where dispensaries are allowed to remain open, according to a new RAND Corporation study. The findings challenge the common wisdom that marijuana dispensaries promote criminal activity.

Studying crime both before and after a large number of dispensaries were shut down in Los Angeles, researchers found that incidents such as break-ins rose in the neighborhoods of closed dispensaries relative to dispensaries allowed to remain open, at least in the short term.

In the blocks with the closed dispensaries, the study observed crime up to 60 percent greater than comparable blocks with open dispensaries, but the effects were not apparent across a wider area.

“If medical marijuana dispensaries are causing crime, then there should be a drop in crime when they close,” said Mireille Jacobson, the study’s lead author and a senior economist at RAND, a nonprofit research organization. “Individual dispensaries may attract crime or create a neighborhood nuisance, but we found no evidence that medical marijuana dispensaries in general cause crime to rise.”

Researchers say the crime detected near closed dispensaries relative to open dispensaries may be caused by factors such as a loss of foot traffic, a resurgence in outdoor drug activity, a change in police efforts such as fewer nearby patrols or a loss of the on-site security provided by dispensaries.

Sixteen states and the District of Columbia have laws allowing medical use of marijuana and at least a half dozen states are debating whether to approve such use as well. The proliferation of medical marijuana dispensaries in places like Los Angeles and Denver has created concerns among police and neighborhood activists that the outlets attract crime and create a public nuisance.

However, the claim that marijuana dispensaries are linked to crime has not been rigorously evaluated and the RAND study is the first systematic analysis of the link between medical marijuana dispensaries and crime.

RAND researchers examined crime reports for the 10 days prior to and the 10 days following June 7, 2010, when the city of Los Angeles ordered more than 70 percent of the city’s 638 medical marijuana dispensaries to close. One of the principal reasons behind the city’s effort was to limit dispensaries because of the presumed connection to crime. Researchers limited their analysis to 10 days because court challenges prompted some closed dispensaries to reopen.

In addition to examining crime around closed dispensaries, researchers also collected details about crime during the same period near dispensaries that did not close and dispensaries in surrounding communities such as West Hollywood, Beverly Hills and unincorporated areas of Los Angeles County.

The information allowed researchers to analyze crime reports within a few blocks around dispensaries that closed and compare that information to crime reports for neighborhoods where dispensaries remained open. In total, researchers examined 21 days of crime reports for 600 dispensaries in Los Angeles County—170 dispensaries remained open while 430 were ordered to close.

The ongoing analysis found that crimes reported near closed dispensaries remained relatively flat while reports of crime near the remaining dispensaries decreased, suggesting a relative increase in crime around closed dispensaries.

The study found about 60 percent more reports of crime within three blocks of a closed dispensary relative to the same distance around an open dispensary. The effect diminished with distance: within six blocks of a closed dispensary crime increased by 25 percent and by 10 blocks there was no perceptible change in crime.

Researchers say the effects are concentrated on crimes such as break-ins that may be particularly sensitive to the presence of security. Reports of breaking and entering climbed by about 50 percent within three blocks of closed dispensaries relative to the change around open dispensaries.

Researchers say their findings should be interpreted cautiously, given that they studied a relatively short period of time and that the margin of error was high. But the study may help inform decisions being made by local and state officials about how to regulate medical marijuana dispensaries.

The study, “Regulating Medical Marijuana Dispensaries: An Overview with a Case Study of Los Angeles Preliminary Evidence of Their Impact on Crime,” is available at www.rand.org.

Support for the study was provided by the Robert Wood Johnson Foundation’s Public Health Law Research program. Other authors of the study are Tom Chang, James M. Anderson, John MacDonald, Ricky Bluthenthal and Scott C. Ashwood.

The project was conducted within the RAND Safety and Justice Program, which conducts public policy research on corrections, policing, public safety and occupational safety.

By  |  11:45 AM ET, 10/13/2011

 
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