Background and Objective:
Associations between off-premise alcohol outlet density and violent crime have been well established and explained partly by availability theory, which posits that greater access to alcohol leads to greater intoxication-related violence. However, few studies have investigated the effectiveness of alcohol outlet zoning policies in reducing alcohol misuse and violent crime in low-income neighborhoods. By adopting a systems approach, this study aimed to 1) model the interconnected individual, social, and environmental factors shaping substance misuse and violent crime; and 2) simulate the potential impacts of alcohol outlet zoning policies on these outcomes.

Methods:
We developed a spatial agent-based model representing a low-income, predominantly black neighborhood in Baltimore City, which was impacted by a recent amendment to the city’s alcohol zoning code. Informed by a conceptual framework developed using a community-based participatory approach, we characterized residents’ routine activities (e.g., alcohol and drug use, purchasing behavior) and social interactions. The model was calibrated and validated using empirical data and used to simulate various policy scenarios. RESULTS. Most simulated policy scenarios appeared ineffective in reducing alcohol consumption, even with the closure of over half the neighborhood alcohol outlets. In contrast, our findings suggest that illicit drug use could increase as some alcohol misusers may turn to illicit substances for self-medication. Consequently, the policies could have the unintended consequence of increasing both alcohol and drug-related crimes by driving residents to purchase and gather at alternate stores and outside of their neighborhoods.

Conclusions:
Our modelling shows the possible limitations of using alcohol availability theory to support reductions in alcohol outlet density and thereby crime. It also highlights the need for community engagement to understand the complex and multi-level dynamics that shape patterns of alcohol misuse and violent crime in neighborhoods, to minimize the potential for unintended consequences.