According to roughly a dozen recent studies, executions save lives. For each inmate put to death, the studies say, 3 to 18 murders are prevented.
The effect is most pronounced, according to some studies, in Texas and other states that execute condemned inmates relatively often and relatively quickly.
The studies, performed by economists in the past decade, compare the number of executions in different jurisdictions with homicide rates over time — while trying to eliminate the effects of crime rates, conviction rates and other factors — and say that murder rates tend to fall as executions rise. One influential study looked at 3,054 counties over two decades.
“I personally am opposed to the death penalty,” said H. Naci Mocan, an economist at Louisiana State University and an author of a study finding that each execution saves five lives. “But my research shows that there is a deterrent effect.”
(via Bruno Gonçalves)