Evaluating Medical Marijuana Dispensary Policies: Spatial Methods for the Study of Environmentally-Based Interventions

Bridget Freisthler, Nancy J. Williams, Revel Sims, Scott E. Martin

In 1996, California was the first state to pass a Compassionate Use Act allowing for the legal use of marijuana for medicinal purposes. Here we review several current policy and land use environmental interventions designed to limit problems related to the influx of medical marijuana dispensaries across California cities. Then we discuss the special challenges, solutions, and techniques used for studying the effects of these place-based policies. Finally, we present some of the advanced spatial analytic techniques that can be used to evaluate the effectiveness of environmental interventions, such as those related to reducing problems associated with the proliferation of medical marijuana dispensaries. Further, using data from a premise survey of all the dispensaries in Sacramento, this study will examine what characteristics and practices of these dispensaries are related to crime within varying distances from the dispensaries (e.g., 100, 250, 500, and 1000 feet). We find that some security measures, such as security cameras, having a door man outside, and having signs requiring an ID prescription card, taken by medical marijuana dispensary owners might be effective at reducing crime within the immediate vicinity of the dispensaries.

Differences in Violent Crime by Security Measures in Sacramento

Dispensaries with a locked metal screen door at the entrance to the dispensary had a higher average violent crime rate within 500 feet. Violent crime rates at other distances were not significantly related to having a locked metal screen door.

Having a pass through on the door as a security measure was not related to violent crime rates within 100, 250, 500, or 1000 feet of a dispensary.

MMDs with a visible door man outside of the establishment had a significantly lower rate of violent crime within 250 feet of the dispensary. Although the dispensaries with door man had lower rates of crime at 100, 500, and 1000 feet, these findings were not statistically significant.

Dispensaries with visible security cameras had statistically significantly lower rates of violent crime within a 100 and 250 feet radius of the dispensary. By 500 feet, however, there was no difference in the average rate of violent crime for those dispensaries with a security camera and those without.

Lower rates of violent crime are found within 100 and 250 feet of dispensaries for those MMDs that have a sign stating that an identification prescription card was required. At 500 and 1000 feet, those dispensaries requiring a prescription id card continued to have lower rates of violent crime but these differences were no longer statistically significant.

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