home. Both Kellermann and Reay (1986) and Rushforth et al. (1974) compare fatalities caused by self-defense and other motivations. Both studies find that people using guns in self-defense account for a small fraction of fatalities in the home. Kellermann and Reay find that there were nearly 5 times as many homicides and 37 times as many suicides as perpetrators killed in self-defense. They go on to conclude, “The advisability of keeping a firearm in the home for protection must be questioned.” Rushforth et al. (1974) found similar results and drew similar conclusions.

Although the facts are in no doubt, the conclusions do not seem to follow. Certainly, effective defensive gun use need not ever lead the perpetrator to be wounded or killed. Rather, to assess the benefits of self-defense, one needs to measure crime and injury averted. The particular outcome of an offender is of little relevance. It might be, as Kleck (2001b) suggests, that the ratio of firearm-caused fatalities to fatalities averted because of defensive gun use is a more relevant comparison. Answering this question, however, requires researchers to address the fundamental counterfactual questions regarding the effects of both defensive and offensive uses of firearms that have been the subject of much of this report and have generally proved to be elusive. Simple death counts cannot answer these complex questions.

Case-control sampling schemes matching homicide victims to non-victims with similar characteristics have also been used to infer whether owning a firearm is a risk factor for homicide and the utility of firearms for self-defense (see Chapter 7 for a discussion of the case-control methodology). Kellermann et al. (1993) found that persons who had a firearm in the home were at a greater risk for homicide in their home than persons who did not have a firearm (adjusted odds ratio of 2.7). Cummings et al. (1997) found that persons who purchased a handgun were at greater risk for homicide than their counterparts who had no such history (adjusted odds ratio of 2.2).

In light of these findings, Kellermann et al. (1993) ultimately conclude that owning firearms for personal protection is “counterproductive,” (p. 1087) and that “people should be strongly discouraged from keeping guns in the home” (p. 1090). This conclusion rests on the implicit assumption that the decision to own a firearm is random or exogenous with respect to homicide in the home (after controlling for various observed factors, including whether a household member has been hurt in a fight, has been arrested, or has used illicit drugs). Cummings and his colleagues (1997) do not draw such strong causal conclusions, but instead simply describe the observed positive association between firearms and homicide.

In the committee’s view, the exogenous selection assumption and the resulting conclusions are not tenable. While these observed associations between firearms ownership and homicide may be of interest, they do little to reveal the impact of firearms on homicide or the utility of firearms for



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