A study by the American Journals of Public Health has indicated that US states with higher estimated rates of gun ownership experience a higher number of firearms-related homicides. The study, covering 30 years (1981-2010) in all 50 states, found a “robust correlation” between estimated levels of gun ownership and actual gun homicides at the state level, even when controlling for factors typically associated with homicides. For each 1 percentage point increase in the prevalence of gun ownership, the state firearm homicide rate increases by 0.9 per cent, the authors found.

The study, led by a Boston University School of Public Health researcher, examines the National Rifle Association’s (NRA) claim that increased gun ownership does not lead to increased gun violence. A Boston University School of Public Health release reports that it is the largest study conducted to date into the correlation between gun ownership and firearms violence, and the first comprehensively to examine the issue since the tragic shooting last December of 20 children and seven adults at Sandy Hook Elementary School in Newtown, Connecticut.

Researchers led by Dr Michael Siegel, professor of community health sciences at the Boston University School of Public Health, examined data for the years 1981-2010 on state firearm homicide rates from the Center for Disease Control and Prevention’s Web-based Injury Statistics Query and Reporting System (WISQUARS) database.

The release notes that all other factors being equal, for example, the model predicts that if the gun ownership estimate for Mississippi were 58 per cent (the average for all states), instead of 77 per cent (the highest of all states), its firearm homicide rate would be 17 per cent lower.

The study found that over the three decades, the mean estimated percentage of gun ownership ranged from a low of 25.8 per cent in Hawaii to a high of 76.8 per cent in Mississippi, with an average over all states of 57.7 per cent.

The mean age-adjusted firearm homicide rate ranged from a low of 0.9 per 1,00,000 population in New Hampshire to a high of 10.8 per 1,00,000 in Louisiana over the three decades, with an average for all states of 4 per 1,00,000. For all states, the average firearm homicide rate decreased from 5.2 per 1,00,000 in 1981 to 3.5 per 1,00,000 in 2010.