Association of Housing Instability With Firearm Homicides in Major US Cities

Introduction: Multiple social determinants of health have been linked to gun violence; however, the specific role of housing instability (HI) in contributing to firearm homicide rates remains underexplored. We hypothesized that greater HI would be associated with higher firearm homicide rates. Methods: This cross-sectional study analyzed 2021 firearm homicide data from the Centers for Disease Control and Prevention across the 50 largest US metropolitan statistical areas. Measures of HI were collected from the National Low-Income Housing Coalition, U.S. Department of Housing and Urban Development, and the National Housing Preservation Database. HI metrics included rental housing shortages, cost burden severity, income distribution, homelessness rates, and availability of federal housing subsidies. Spearman correlation and linear regression analyses were used to assess the relationship between HI and firearm homicide rates per 100,000 population. Results: Of the 17,037 firearm homicides recorded in 2021, 12,111 (71.1%) occurred within the 50 MSAs studied. On univariate analysis, higher rates of low-income renter households (β = 0.37, P = 0.01) and greater housing subsidies per unhoused person (β = 0.52, P = 0.04) were associated with increased firearm homicide rates. However, in multivariable regression models controlling for race and income distribution, a greater shortage of affordable rental homes for low-income households was associated with higher firearm homicide rates (β = 0.47, σ = 0.1, P < 0.001). Overall, homelessness was not associated with firearm homicide rates. Conclusions: Measures of HI are associated with firearm homicide rates in major US metropolitan areas. These findings highlight the complex relationship between housing insecurity and gun violence and suggest potential targets for policy intervention.