Bang for the buck: The impact of political financial contributions on firearm law.

BACKGROUND: One hundred thousand Americans are shot annually, and 39,000 die. State laws restricting firearm sales and use have been shown to decrease firearm deaths, yet little is known about what impacts their passage or repeal. We hypothesized that spending by groups that favor firearm restrictive legislation would increase new state firearm restrictive laws (FRLs) and that states increasing these laws would endure fewer firearm deaths. METHODS: We acquired 2013 to 2018 state data on spending by groups against firearm restrictive legislation and for firearm restrictive legislation regarding lobbying, campaign, and independent and total expenditures from the National Institute on Money in State Politics. State-level political party representation data were acquired from the National Conference of State Legislatures. Mass shooting data were obtained from the Mass Shooter Database of the Violence Project, and firearm death rates were obtained from Centers for Disease Control Wide-ranging Online Data for Epidemiologic Research and Federal Bureau of Investigation Uniform Crime Reporting databases. Firearm restrictive laws were obtained from the State Firearms Law Database. A univariate panel linear regression with fixed effect for state was performed with change in FRLs from baseline as the outcome. A final multivariable panel regression with fixed effect for state was then used. Firearm death rates were compared by whether states increased, decreased, or had no change in FRLs. RESULTS: Twenty-two states gained and 13 lost FRLs, while 15 states had no net change (44%, 26%, and 30%; p = 0.484). In multivariable regression accounting for partisan control of state government, for-firearm restrictive legislation groups outspending against-firearm restrictive legislation groups had the largest association with increased FRLs (ß = 1.420; 95% confidence interval, 0.63-2.21; p < 0.001). States that gained FRLs had significantly lower firearm death rates (p < 0.001). Relative to states with no change in FRLs, states that lost FRLs had an increase in overall firearm death of 1 per 100,000 individuals. States that gained FRLs had a net decrease in median overall firearm death of 0.5 per 100,000 individuals. CONCLUSION: Higher political spending by groups in favor of restrictive firearm legislation has a powerful association with increasing and maintaining FRLs. States that increased their FRLs, in turn, showed lower firearm death rates. LEVEL OF EVIDENCE: Epidemiological, level I.