New York City Adds Street Lighting to Reduce Crime in Public Housing

In summer 2014, New York City installed brighter exterior lighting and more than 150 temporary light towers in 15 high-crime public-housing developments. The $210 million initiative also kept community centers open later and shifted police focus to precision policing that targeted individuals driving violence rather than low-level offenses.

University of Pennsylvania conducted a randomized controlled trial across 80 housing developments. Serious nighttime outdoor crime dropped 35 percent in areas with added lighting and showed no displacement to other locations. A follow-up study three years later found the reduction persisted.

Similar lighting upgrades in Philadelphia correlated with a 15 percent drop in outdoor nighttime street crimes and a 21 percent drop in outdoor nighttime gun violence. Studies in Philadelphia linked vacant-lot greening to a 29 percent reduction in gun violence and a 9 percent drop in overall crime.

Fixing derelict buildings there coincided with a 39 percent decline in gun violence. , associated tree planting with a 9 percent fall in gun violence. Research by Harvard sociologist Robert Sampson has shown that familiar faces and loose social connections in public spaces can increase mutual obligation and reduce anti-social behavior.