Assessing the impacts of alcohol outlets on crime as a natural experiment: agglomeration, churning and spatial effects

Background and aims Retail alcohol outlets appear to open in neighborhoods with low land and structure rents near sources of demand; they may 'agglomerate', open near to one another or 'churn', replace one another, over time. We used the turnover in numbers of outlets over time to measure agglomeration and churning and the impacts of openings and closings of outlets on neighborhood crime. Design Interrupted quasi-experiments using spatial panel population data from 3768 synthetic block areas over 6 years. Setting City of Oakland, CA, USA. Participants City population. Measurements Census-based socio-demographic estimates and counts of openings and closings of bars/pubs, restaurants and off-premises outlets related to assault, burglary and robbery crime incidents across synthetic Census blocks. Bayesian space-time models were used to assess agglomeration and churning and measure impacts of openings/closings on crime. Findings Churning was substantial; openings followed closings for all outlets [bars/pubs, relative risk (RR) = 50.9, 95% credible interval (CI) = 3.0-449.9; restaurants, RR = 3.1, CI = 1.5-6.1; off-premises, RR = 23.5, CI = 2.0-129.8]. Bars/pub and restaurant openings agglomerated with other outlets (e.g., RR = 1.02, CI = 1.00-1.03 and RR = 1.01, CI = 1.00-1.01), but off-premises outlets did not. Covarying out effects related to outlet densities, bar/pub openings were related to a 3.5% increase in assaults (RR = 1.04, CI = 1.01-1.06) and 6.9% increase in robberies (RR = 1.07, CI = 1.03-1.11). Restaurant openings were related to a 5.3% increase in burglaries (RR = 1.05, CI = 1.04-1.06). Openings and closings of off-premises outlets were unrelated to all three crime types. Conclusions Retail alcohol outlets appear to follow a pattern of opening near to one another and replacing each other over time. Bar, pub and restaurant openings appear to be related to increases in neighborhood crime.