Does Defensive Gun Use Deter Crime?

We study the opposing deterrent and enabling effects of guns carried by law-abiding citizens on violent crime, using the location of shooting ranges as an instrument. Our incident-level data based on admittedly imperfect data from the Gun Violence Archive suggests that defensive gun use (DGU) by crime victims may decrease the probability of their injury or death, while increasing the risk of death or injury by the criminal suspects. However, in the aggregate, higher numbers of defensive gun uses--which proxies for more gun carrying and use--are associated with higher numbers of violent crimes, injuries, and fatalities among victims and suspects alike. We hypothesize that this equilibrium effect arises because more guns being carried and used by citizens produce more incentive and opportunities for criminals to acquire guns, leading to a commensurate increase in the incidence and lethality of crime. In summary, our analysis supports the conclusion that the widespread carrying and use of guns is overall more likely to enable violent crimes than to deter them