Getting off Death Row: Commuted Sentences and the Deterrent Effect of Capital Punishment
利用美国1977-1997年各州面板数据，研究发现每执行一次死刑可减少约5起杀人案，而每减刑一次则增加相同数量的杀人案，但死刑对抢劫、盗窃等非暴力犯罪无影响。
This paper merges a state‐level panel data set that includes crime and deterrence measures and state characteristics with information on all death sentences handed out in the United States between 1977 and 1997. Because the exact month and year of each execution and removal from death row can be identified, they are matched with state‐level criminal activity in the relevant time frame. Controlling for a variety of state characteristics, the paper investigates the impact of the execution rate, commutation and removal rates, homicide arrest rate, sentencing rate, imprisonment rate, and prison death rate on the rate of homicide. The results show that each additional execution decreases homicides by about five, and each additional commutation increases homicides by the same amount, while an additional removal from death row generates one additional murder. Executions, commutations, and removals have no impact on robberies, burglaries, assaults, or motor‐vehicle thefts.