Evaluating the Change in Medical Marijuana Dispensary Locations in Los Angeles Following the Passage of Local Legislation.

In May 2013, Los Angeles voters approved Proposition D, a regulatory measure that set zoning restrictions and capped the number of dispensaries at those that opened before 2007. Specifically, Proposition D stated that only 135 dispensaries were allowed to be in operation and set zoning restrictions prohibiting dispensaries from operating in certain areas. We first assessed whether the legislation changed the physical availability of medical marijuana via dispensaries in Los Angeles. We then used two data points 1 year prior to and 1 year following the implementation of Proposition D to determine if the locations of where the dispensaries are located changed after the enactment of Proposition D. Using a cross-sectional, ecological design, we investigated the change in dispensaries from 2012 to 2014 for Census tracts within the city of Los Angeles (N = 1000). We analyzed data using spatial error regression models that included controls for spatial autocorrelation due to the spatial structure of the data. We found that while the total number of dispensaries in Los Angeles remained largely unchanged, the spatial distribution of dispensaries did change in meaningful ways. Census tracts with more dispensaries in 2014 were significantly and positively associated with the proportion of African American residents and negatively associated with the percent of area that was commercially zoned. In other words, dispensaries opened in areas with a higher proportion of Black residents and closed in Census tract areas that had a higher percentage of commercially zoned land. Findings from this study highlight the importance of continuously regulating dispensary locations. Results suggest that likely as a result of changing regulations, dispensaries may be attempting to conceal their presence and locate in areas that will not advocate against their presence.