A newly released study suggests that increasing residential zoning on blocks that are otherwise zoned commercially might be a viable means of reducing crime in urban areas.

The study, published in the University of Pennsylvania Law Review, finds that city blocks zoned exclusively for residential uses, as well as those zoned for residential and commercial (mixed) uses have less crime than blocks that are zoned solely for commercial use. The research shows that single-use commercially zoned blocks have expected crime rates that are about 45 percent higher than blocks with residential uses mixed in.

Overall, crime was lowest on blocks zoned for residential-only uses, even in relatively high crime neighborhoods. This is contrary to predictions from some urban planning theories that suggest that mixed land-use zoning should lead to the lowest crime rates.

 The study also found that when neighborhoods undergo some change in zoning, mostly by incorporating residential uses, crime drops more than it does in neighborhoods with comparable crime trends before the zoning change. In these cases, crime dropped by about 7 percent on average, mostly as a result of fewer automobile-related property crimes.

James M. Anderson, JD, of RAND, and John M. MacDonald, PhD, of the University of Pennsylvania, along with their colleagues, examined the relationship between land-use law, the built environment and crime. The researchers examined detailed crime data and conducted careful observation of 205 blocks in eight different relatively high-crime areas of Los Angeles. They then analyzed the relationship between changes in land-use zones and crime in all neighborhoods in Los Angeles.

Policymakers have long debated the effect that the built environment has on crime. Some experts have urged diverse uses of land in order to create an urban environment that encourages “eyes on the street” to deter crime. Preventing crime through the built environment eases the burden on the criminal justice system and prevents a wide range of negative health outcomes associated with crime.

To date there has been relatively little objective research designed to test these theories and most of the studies that have occurred have focused on older cities in the eastern United States. This study uses stronger scientific methods than previous studies and focuses on a younger city – Los Angeles – that has land-use patterns that are more typical of where urban growth is occurring today.

This study was funded through a grant provided by the Robert Wood Johnson Foundation’s Public Health Law Research program.

Read the study at the University of Pennsylvania Law Review