Does the Right to Carry Concealed Handguns Deter Countable Crimes? Only a Count Analysis Can Say
使用广义泊松过程分析美国各州携带隐藏手枪法律对谋杀、强奸和抢劫报告数量的影响，发现该法律在不同犯罪类型、州和时间上具有统计显著的威慑效应。
An analysis of the effects of right‐to‐carry laws on crime requires particular distributional and structural considerations. First, because of the count nature of crime data and the low number of expected instances per observation in the most appropriate data, least‐squares methods yield unreliable estimates. Second, use of a single dummy variable as a measure of the nationwide effect of right‐to‐carry laws is likely to introduce geographical and intertemporal aggregation biases into the analysis. In this paper, we use a generalized Poisson process to examine the geographical and dynamic effects of right‐to‐carry laws on reported homicides, rapes, and robberies. We find that the effects of such laws vary across crime categories, U.S. states, and time and that such laws appear to have statistically significant deterrent effects on the numbers of reported murders, rapes, and robberies.