A new study conducted by University of Michigan and Harvard University has found areas in Detroit where more than a few demolitions took place experienced an 11 percent drop in gun violence. In addition, the study found this did not result in an uptick of such incidents in nearby neighborhoods.
The analysis was led by Jonathan Jay, a scholar with the Firearm Safety Among Children and Teens (FACTS) coalition based at University of Michigan. Jay and colleagues combined data from the Detroit Demolition Program with data from law enforcement on serious assaults and homicides committed with firearms in the areas where demolitions occurred.
Detroit’s demolition program has been targeting abandoned houses and other buildings in the city’s most blight-stricken neighborhoods over the past decade.
The study found that the clearest drops in firearm deaths and injuries occurred in areas where six to 12 abandoned buildings were demolished in the first 18 months of the demolition program. Areas where fewer buildings were demolished had smaller drops.
“Firearm assaults in Detroit were already declining during the time of this study, but they went down faster in areas where six or more buildings were demolished,” Jay says on University of Michigan’s website. “This is good evidence, and the first we know of, that demolitions are associated with reduced gun violence.”
The study found the decline in gun violence wasn’t spread evenly across the city. Neighborhoods with the highest concentrations of non-Hispanic white residents in Detroit, which is a majority-black city, were most likely to have the rate of demolition associated with the steepest drop in firearm deaths and injuries.
“This says something about access to political power or other resources, and is problematic,” Jay says.
The program was associated with larger reductions in firearm assaults for the locations receiving a moderate numbers of demolitions (between 6 and 12), the study says, than for locations receiving high numbers of demolitions (13 and over). The researchers estimate this is because of the challenges of physical upkeep in these properties.
The fact that gun violence didn’t appear to shift from neighborhoods where demolitions took place to nearby areas without as many demolitions is encouraging, the researchers said.
“We often hear that place-based prevention programs simply move the crime elsewhere, but this study and others we have done indicate consistently that such declines do not translate into increases elsewhere,” says Marc Zimmerman, the co-director of FACTS who helped conduct the study. “Place-based change helps reduce opportunities for crime and for negative social interactions and begins to rebuild neighborhoods to be places where people are not afraid to be outside and talk to one another.”
The team hopes their research can inform demolition efforts in other cities that are working to clear abandoned buildings.
“Abandoned buildings and vacant overgrown lots are places where violence is more likely to occur and where firearms can be stored,” Jay says. “While demolition removes abandoned buildings, it also creates a vacant lot, so it had not been clear whether demolition would affect neighborhood-level gun violence rates.”
Starting in areas with higher levels of gun violence may pay the largest dividends, Jay says. But it will also be important to study how demolitions in cities with higher population densities, rather than Detroit’s predominance of single-family homes, correlate with gun violence rates.
“It appears from our analysis that the largest effect might come from dispersing the demolition effort throughout the city, rather than concentrating the effort on removing all abandoned structures in a few areas, given limited resources,” Jay says. “It’s also important to look at alternatives to demolition for houses and other structures that might be salvageable, especially in cities with large homeless populations or housing affordability problems.”
The study appears in the Journal of Behavioral Medicine.