Objective: To examine whether business improvement districts (BID) contributed to greater than expected declines in the incidence of violent crimes in affected neighbourhoods.
Method: A Bayesian hierarchical model was used to assess the changes in the incidence of violent crimes between 1994 and 2005 and the implementation of 30 BID in Los Angeles neighbourhoods.
Results: The implementation of BID was associated with a 12% reduction in the incidence of robbery (95% posterior probability interval -2 to 24) and an 8% reduction in the total incidence of violent crimes (95% posterior probability interval -5 to 21). The strength of the effect of BID on robbery crimes varied by location.
Conclusion: These findings indicate that the implementation of BID can reduce the incidence of violent crimes likely to result in injury to individuals. The findings also indicate that the establishment of a BID by itself is not a panacea, and highlight the importance of targeting BID efforts to crime prevention interventions that reduce violence exposure associated with criminal behaviours.