Interesting conclusions from the authors of the study:
"A number of limitations should be considered when interpreting the findings from this study. First, our study was based on data from death certificates and proxy interviews. The accuracy and completeness of information from these types of data sources can vary. With death certificates, for instance, there is the possibility of misclassification regarding the cause or manner of death. In the case of proxy interviews, knowing the outcome might have introduced bias in assessing behavioral or psychological characteristics of the decedent prior to death. The nature, degree, or direction of recall bias among proxies reporting on violent deaths versus nonviolent deaths is not known, however. Second, the gun in the home may not have been the gun used in the death.
Third, it is possible that the association between a gun in the home and risk of a violent death may be related to other factors that we were unable to control for in our analysis. For instance, with homicide, the association may be related to certain neighborhood characteristics or the decedent’s previous involvement in other violent or illegal behaviors. Persons living in high-crime neighborhoods or involved in illegal behaviors may acquire a gun for protection. The risk comes not necessarily from the presence of the gun in the house but from these types of environmental factors and exposures.
Fourth, our analysis was restricted to violent deaths in the home. The dynamics of homicides or suicides occurring in other locations may be very different. However, the degree of bias with suicide is likely to be small given that over three quarters of all suicides (76.3 percent) in this nationally representative sample occurred in the home; of those that occurred outside the home, 52.7 percent were committed with a firearm. Finally, our study focused on fatal outcomes for a sample of decedents. We were unable to ascertain the risk of a nonfatal outcome and were also unable to weigh the risk of a violent death against any protective benefits of gun ownership."
There is also no measurement of the utility of firearms to the owner. We accept the risk of travel in automobiles because of perceived utility; likewise, the pleasure derived from the use of alcohol is not outweighed by the tens of thousands of deaths attributed to its use each year.