This story originally appeared in The Philadelphia Inquirer.

Frayed wiring, a leaky roof, or deteriorating walls plague thousands of Philadelphia homes, especially its aging rowhouses. With help from the Philadelphia Housing Development Corporation’s (PHDC) Basic Systems Repair Program (BSRP), nearly 5,000 homeowners meeting income criteria received free essential home repairs between 2018 and 2020. According to research from the University of Pennsylvania, these homeowners may have benefited with more than just a safer home.

In a study published last week, researchers tracked crime levels over time and found that when BSRP funded repairs for even just one house on a block, crime on that block was reduced by nearly 22%.

“I was pleasantly surprised,” said David Thomas, president and CEO of the PHDC, who was not involved in the study. “People have so much stress when they live in poor conditions … if we can relieve some of that stress, I think that goes a long way.”

These findings come at a time when the city is grappling with a homicide rate that dwarfs recent years. In July, Philly marked its 300th homicide victim of the year — the earliest in the year that killings have reached those levels since the early 1990s.

Lead study author Eugenia South, an assistant professor of emergency medicine at the Hospital of the University of Pennsylvania, was interested in disentangling the social and structural factors that brought patients into the ER.

“When we look at any given health outcome, they are really patterned by neighborhood,” she said, pointing to high rates of chronic disease in North, West, and Southwest Philly. “It’s because of structural racism,” she added, which leads to disinvestment in health-promoting resources — such as outdoor spaces and nutritious food sources — in neighborhoods predominantly populated by people of color and low-income people.

It can also lead to disinvestment in housing. When South, faculty director of the Penn Urban Health Lab, looked at a map of BSRP-repaired homes, she noticed it mirrored other patterns of disinvestment. A majority of the homeowners were Black and Latino, and the repairs were most common in North and West Philadelphia.

Vincent Reina, an associate professor of planning and urban economics and the faculty director of the Housing Initiative at Penn, wanted to figure out how investing in a neighborhood could improve a community’s health. Policy decisions often came down to deciding where to invest limited funds for the greatest impact, which made it important to quantify the impact of BSRP — a relatively inexpensive program because repairs usually cost less than $20,000 per home.

“Tying those place-based investments to real outcomes for individuals has become a priority for planners as we’ve made the case for the multiple ways in which these investments could affect someone’s livelihood,” Reina said.

South, Reina, and Penn professor of criminology John MacDonald grouped all the homes in Philly by block face — one side of a city block — and identified all the homes that received BSRP repairs between 2006 and 2013. They then compared the crime rate on the block before and after the repairs. Since crime may have changed over that time for other reasons, they compared blocks with BSRP repairs to blocks with homes on the BSRP waitlist, which were similar in many other ways but didn’t actually get repairs.

They found that when a BSRP repair happened on a block, crime rate on the block face decreased by 21.9%. There were similarly large decreases for specific types of crime, including assault, robbery, and homicide. Moreover, South and Reina were surprised to see that for every additional house that received BSRP repairs, the crime rate continued to drop, up to around four houses.

“It shows even the investment in one home actually is really important,” Reina said.

The researchers emphasized that they can’t be sure that BSRP repairs are causing — and not just correlated with — a decrease in crime. But they think their results strongly suggest that investing in repairs can fortify a neighborhood against crime.

“Place impacts people,” South said. “The social fabric of a neighborhood is very connected to the physical environment.”

For example, when a poorly maintained house has to be demolished, it affects the neighborhood’s integrity and values, Thomas said. Deteriorating homes and vacant lots can also make communities feel neglected and disrupt connections with neighbors that might otherwise encourage collective responsibility and help prevent crime, South said.

Living in these homes can also hurt residents’ physical and mental health: for example, leaks can foster mold growth that cause respiratory symptoms. In future work, South hopes to narrow down the specific health consequences that are headed off through BSRP repairs. Reina is also hoping to figure out which kinds of repairs have the greatest association with reducing crime.

Thomas said this study justifies increasing the scale of the BSRP. However, funding is key — cash from a 2017 bond was essential to the last BSRP expansion that cut the three-year waiting list to less than a year.

South sees home repairs as another tool to reduce crime — especially gun violence, an escalating epidemic in Philly — alongside a growing list of evidence-based community, built environment, and individual-level interventions. She is discussing these findings with the PHDC, policymakers, activists, and academics to encourage everyone to invest more resources into place-based interventions.

“When you’re thinking about gun violence prevention as a whole, there’s no one thing that’s going to get rid of it,” South said. “You need to have a multifaceted approach to prevention.”

The Germantown Info Hub is one of over 20 news organizations producing Broke in Philly, a collaborative reporting project on solutions to poverty and the city’s push towards economic justice. Follow us at @BrokeInPhilly.