Background
The introduction of laws that permit the use of marijuana for medical purposes has led to the emergence of a medical marijuana industry in some US states. This study assessed the spatial distribution of medical marijuana dispensaries according to estimated marijuana demand, socioeconomic indicators, alcohol outlets and other socio-demographic factors.
Method
Telephone survey data from 5,940 residents of 39 California cities were used to estimate social and demographic correlates of marijuana demand. These individual-level estimates were then used to calculate aggregate marijuana demand (i.e. market potential) for 7,538 census block groups. Locations of actively operating marijuana dispensaries were then related to the measure of demand and the socio-demographic characteristics of census block groups using multilevel Bayesian conditional autoregressive logit models.
Results
Marijuana dispensaries were located in block groups with greater marijuana demand, higher rates of poverty, alcohol outlets, and in areas just outside city boundaries. For the sampled block groups, a 10% increase in demand within a block group was associated with 2.4% greater likelihood of having a dispensary, and a 10% increase in the city-wide demand was associated with a 6.7% greater likelihood of having a dispensary.
Conclusion
High demand for marijuana within individual block groups and within cities is related to the location of marijuana dispensaries at a block-group level. The relationship to low income, alcohol outlets and unincorporated areas indicates that dispensaries may open in areas that lack the resources to resist their establishment.