Hot, Cross, Guns

Abstract

The correlation between hot temperatures and crime is well documented, though the relationship between heat and gun violence faces confounding problems of misreporting and underreporting of crimes. In this research, we utilize ShotSpotter data which record the time and location of gunshots via listening devices that are distributed across select cities, and we link these data with information on temperature variation over time. These data allow us to circumvent the concern that gun violence may be underreported or unobserved in standard sources like the Uniform Crime Reporting records. Here, we show that the marginal effect of a 1F change in the daily maximum temperature increases gunshot counts within a city by approximately 0.6%, and that a 1F change increases the probability that a gunshot occurs. Under expected warming paths, this implies at least a 1.6% increase in gunshots daily, and an increase in the rate of firearm deaths due to assault and suicide.