A study conducted between 2006 and 2013 involving urban renovations for low-income Philadelphia neighborhoods revealed an incidental side effect. In the study of 13,000 recipients, blocks with home repairs experienced 22% less crime overall and 22% fewer homicides. What is more, the positive effects lasted throughout the duration of the six-year study. "It's not an instant reduction that then gets washed out a year later," said Vincent J. Reina, an associate professor at the University of Pennsylvania and a co-author of the report. The results echo a criminal justice theory that neighborhood buildings well-cared for are associated with positive neighborhood dynamics. But the key priority of the renovations, Reina says, is actually to make sure residents have a safe place to live so they don't need to worry about the roof caving in during the night. It's protecting people from inside their house, said Reina.