Illuminating Crime Prevention: Evidence from Washington, DC's Street Lighting Upgrade

Research summary: We examine how large-scale investments in urban infrastructure influence crime by evaluating Washington, DC’s 2023 citywide conversion of street lighting to LED technology. Using incident-level crime data from 2014 to 2025 and leveraging the staggered rollout of the upgrade, we estimate its effects using a staggered difference-in-differences design. Our primary analysis uses street segment–month data to capture immediate, micro-level impacts at the locations where lighting was upgraded, complemented by broader community-level effects. The results show significant reductions in nighttime offenses, driven largely by financially motivated crimes and some evidence of decreases in gun-related offenses. The effects persist for at least one year after the intervention. Crime did not reallocate to other times of day, and there is no evidence of displacement into adjacent streets.

Policy implications: These findings provide rigorous evidence that citywide street lighting upgrades, implemented primarily for energy efficiency and service delivery, can yield meaningful public safety benefits. By documenting immediate, dynamic, and spatially diffuse crime reductions, this study advances situational crime prevention and environmental criminology while informing policymakers about the conditions under which investments in the built environment can complement, rather than substitute for, enforcement-based strategies.