This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual gun ownership rates at both the state and the county level during the past two decades. My findings demonstrate that changes in gun ownership are significantly positively related to changes in the homicide rate, with this relationship driven entirely by the impact of gun ownership on murders in which a gun is used. The effect of gun ownership on all other crime categories is much less marked. Recent reductions in the fraction of households owning a gun can explain at least one-third of the differential decline in gun homicides relative to non-gun homicides since 1993. I also use this data to examine the impact of Carrying Concealed Weapons legislation on crime, and reject the hypothesis that these laws led to increases in gun ownership or reductions in criminal activity.
