Crime did not rise in every city where housing projects came down. In cities where it did, many factors contributed: unemployment, gangs, rapid gentrification that dislocated tens of thousands of poor people not living in the projects. Still, researchers around the country are seeing the same basic pattern: projects coming down in inner cities and crime pushing outward, in many cases destabilizing cities or their surrounding areas. Dennis Rosenbaum, a criminologist at the University of Illinois at Chicago, told me that after the high-rises came down in Chicago, suburbs to the south and west—including formerly quiet ones—began to see spikes in crime; nearby Maywood’s murder rate has nearly doubled in the past two years. In Atlanta, which almost always makes the top-10 crime list, crime is now scattered widely, just as it is in Memphis and Louisville.

In some places, the phenomenon is hard to detect, but there may be a simple reason: in cities with tight housing markets, Section8 recipients generally can’t afford to live within the city limits, and sometimes they even move to different states. New York, where the rate of violent crime has plummeted, appears to have pushed many of its poor out to New Jersey, where violent crime has increased in nearby cities and suburbs. Washington, D.C., has exported some of its crime to surrounding counties in Maryland and Virginia.