No sales after midnight: evaluating the impact of a business curfew on drug-related crime in San Francisco’s tenderloin

Business curfews are emerging as regulatory policy instruments to reduce crime in high-risk areas, yet rigorous evaluations remain limited. This study examines San Francisco’s Tenderloin Retail Hours Restriction Pilot, which required select businesses to close from 12:00 a.m. to 5:00 a.m. starting July 2024. Using a customized Bayesian Structural Time Series model, we estimate a 56% reduction (95% credible interval: −72% to −27%) in drug-related incidents during curfew hours over nine months, with no evidence of spatial displacement to nearby areas or temporal displacement within the Tenderloin Public Safety Area. Results hold under Causal-ARIMA sensitivity tests. Findings suggest curfews may reduce opportunities for street-level drug activity, but potential economic costs and questions about long-term sustainability underscore the need for careful policy design.