Income Inequality, Household Income, and Mass Shooting in the United States.

Joseph F Cabrera,Roy Kwon

doi:10.3389/fpubh.2018.00294

Abstract

Mass shootings are becoming a more common occurrence in the United States. Data show that mass shootings increased steadily over the past nearly 50 years. Crucial is that the wide-ranging adverse effects of mass shootings generate negative mental health outcomes on millions of Americans, including fear, anxiety, and ailments related to such afflictions. This study extends previous research that finds a strong positive relationship between income inequality and mass shootings by examining the effect of household income as well as the interaction between inequality and income. To conduct our analyses, we compile a panel dataset with information across 3,144 counties during the years 1990 to 2015. Mass shootings was measured using a broad definition of three or more victim injuries. Income inequality was calculated using the post-tax version of the Gini coefficient. Our results suggest that while inequality and income alone are both predictors of mass shootings, their impacts on mass shootings are stronger when combined via interaction. Specifically, the results indicate areas with the highest number of mass shootings are those that combine both high levels of inequality and high levels of income. Additionally, robustness checks incorporating various measures of mass shootings and alternative regression techniques had analogous results. Our findings suggest that to address the mass shootings epidemic at its core, it is essential to understand how to stem rising income inequality and the unstable environments that we argue are created by such inequality.

Highlights

The dramatic increase of mass shootings in the United States over the past few decades is an important topic of investigation for the field of public health
The findings of the negative binomial regression model (Table 1, Model 1), which examines the main predictors net of several control variables, indicates both income inequality (Adjusted IRR 1.46; 95% CI = 1.25, 1.71) and household income (Adjusted IRR 1.53; 95% CI = 1.26, 1.87) produce a statistically significant relationship with incidences of mass shootings
These results suggest that we should see a 0.46 increase in the expected number of mass shootings for every one standard deviation increase in inequality and a 0.53 increase for household income

Summary

Introduction

The dramatic increase of mass shootings in the United States over the past few decades is an important topic of investigation for the field of public health. They are still relatively rare events compared to other forms of violence, mass shootings tend to spread fear and anxiety in the general population in a manner that extends well-beyond their specific geographic origins [1]. We contend counties which simultaneously maintain high levels of income and inequality are the most likely to experience these events We posit this potential interaction effect based on the premise that higher income communities may produce higher levels of frustration and anger resulting from an environment of extreme relative deprivation

Methods

Results

Conclusion