Criminal Deterrence, Geographic Spillovers, and Right-to-Carry Concealed Handguns
研究美国各州通过隐蔽持枪法对本县及邻县犯罪率的影响，发现本县犯罪率下降但邻县犯罪率上升，溢出效应显著且随时间增强，质疑了忽视空间效应的既有研究。
Increased law enforcement or penalties may deter crime, but they may also cause criminals to move to other crimes or other areas. This paper examines whether the adopting a shall issue concealed weapons law in one state alters crime in neighboring areas. The benefits that a county obtains from it's state passing a shall issue concealed handgun law are generally stronger than those found in previous work. Spillover effects on neighboring areas are almost always deleterious. Criminals tend to move across communities more readily in response to changes in concealed handgun laws than in response to changes in arrest rates. The spillover effects are surprisingly large, especially for property crimes, thus questioning existing research which ignores these considerations. The spillovers are immediate and increase over time (with the exception of assaults and auto theft). Except for rapes, the negative effects of a neighbor's law are mitigated by having one's own state adopting the law. Taken together these results imply that concealed handguns deter criminals and that the largest reductions in violent crime will be obtained when all the states adopt these laws. We find little evidence that increased arrest rates create similar spillovers.