Don’t pretend that any opinion on whether a state’s death-penalty law will deter future murderers is based on any remotely credible evidence, says the Denver Post, citing “a consensus of criminologists, economists and other academics who have reviewed deterrence studies from both sides and officially declared them useless.” The National Academy of Sciences picked apart decades of deterrence research last year and recommended “that these studies not be used to inform deliberations” on capital punishment. The academy’s National Research Council noted it had made a similar survey 30 years before and was “disappointed” to learn each study since was equally futile. Such pessimism has not stopped statisticians from attempting proofs and rejections of deterrence.
The Death Penalty Information Center, which opposes capital punishment, points to higher murder rates in states that have the death penalty as proof the sentencing threat does not deter crime. The gap grew in the 1990s, to the point where death- penalty states currently have 35 percent more murders per capita than those who have abolished it. If deterrence worked, how could Texas, which executes a dozen inmates a year, have a higher murder rate than Colorado, which has executed one murderer in more than four decades? “There’s no credible evidence of deterrence,” concludes John Blume, a law professor with the Cornell Death Penalty Project. Death-penalty proponents have all sorts of problems with that comparison. Maybe those states instituted the death penalty because they know they have more murders and want to stop them. How high would the murder rate have gone in those states if they didn’t have executions?