Racial Residential Segregation a Cause of the Black-White Disparity in Firearm Homicide Rates

States with greater residential segregation of Black and White populations have higher racial disparities in fatal firearm homicide, according to a new study published in the Journal of the National Medical Association. Residential segregation has been acknowledged as a fundamental cause of many racial disparities in health, including diseases like cancer, high blood pressure, and diabetes. The study finds states with a greater degree of racial residential segregation have a higher racial disparity in firearm homicide rates, suggesting that firearm homicide can be added to a long list of other adverse health outcomes that have been found to be associated with structural racism in the U.S.

This is one of first studies to examine the relationship between racial residential segregation and firearm homicide fatalities at a state level over a 25-year time period. The researchers controlled for multiple race-specific measures of deprivation in education, employment, economic status, and housing.

“It was important for us to analyze this at the state-level, because in the past we’ve found that a Black person living in Wisconsin has a 22-fold higher risk of being fatally shot compared to a White person, but in New Mexico a Black individual has a 2-fold higher risk of being fatally shot compared to a White person,” said lead author Anita Knopov BUSM’19.

The study used data on annual state-specific firearm homicide rates from the Centers for Disease Control and Prevention (CDC) for the period 1991-2015. To measure racial segregation at the state level, the researchers used a well-established measure called the “index of dissimilarity.” The index of dissimilarity measures the degree of racial integration within neighborhoods across a state. The scale runs from 0 to 100, with higher numbers representing higher levels of racial residential segregation.

The study found that for every 10-point increase in the index of dissimilarity, the ratio of Black to White firearm homicide rates in a state increased by 39 percent. After controlling for levels of White and Black deprivation, racial segregation remained negatively associated with White firearm homicide rates and positively associated with Black firearm homicide rates.