The Death Penalty Saves Lives?

"Those who object to capital punishment, and who do so in the name of protecting life, must come to terms with the possibility that the failure to inflict capital punishment will fail to protect life.” - Cass R. Sunstein, a law professor at the University of Chicago and Adrian Vermeule, a law professor at Harvard.

In the November 18, 2007 issue of the NY Times Adam Liptak raises the question: Does The Death Penalty Save Lives? This is a particularly timely question in view of the fact that the U.S. Supreme Court has in essence suspended all executions in the United States until the question of death by lethal injection as cruel and unusual punishment can be decided.

Paraphrasing Adam’s article he writes:

According to roughly a dozen recent studies, executions save lives. For each inmate put to death 3 to 18 murders are prevented. The studies, performed by economists, compare the number of executions in different jurisdictions with homicide rates over time and say that murder rates tend to fall as executions rise. “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.”

The studies have been the subject of sharp criticism, much of it from legal scholars who say that the theories of economists do not apply to the violent world of crime and punishment. The death penalty “is applied so rarely that the number of homicides it can plausibly have caused or deterred cannot reliably be disentangled from the large year-to-year changes in the homicide rate caused by other factors,” John J. Donohue III, a law professor at Yale with a doctorate in economics, and Justin Wolfers, an economist at the University of Pennsylvania, wrote in the Stanford Law Review in 2005. “The existing evidence for deterrence,” they concluded, “is surprisingly fragile.”

“The evidence on whether it has a significant deterrent effect seems sufficiently plausible that the moral issue becomes a difficult one,” said Cass R. Sunstein, a law professor at the University of Chicago who has frequently taken liberal positions. “I did shift from being against the death penalty to thinking that if it has a significant deterrent effect it’s probably justified.” Professor Sunstein and Adrian Vermeule, a law professor at Harvard, wrote in their own Stanford Law Review article that “the recent evidence of a deterrent effect from capital punishment seems impressive, especially in light of its ‘apparent power and unanimity,’ ” quoting a conclusion of a separate overview of the evidence in 2005 by Robert Weisberg, a law professor at Stanford, in the Annual Review of Law and Social Science. “Capital punishment may well save lives,” the two professors continued. “Those who object to capital punishment, and who do so in the name of protecting life, must come to terms with the possibility that the failure to inflict capital punishment will fail to protect life.”

To a large extent, the participants in the debate talk past one another because they work in different disciplines. “You have two parallel universes — economists and others,” said Franklin E. Zimring, a law professor at the University of California, Berkeley, and the author of “The Contradictions of American Capital Punishment.” To economists, it is obvious that if the cost of an activity rises, the amount of the activity will drop. To many economists, then, it follows inexorably that there will be fewer murders as the likelihood of execution rises. “I am definitely against the death penalty on lots of different grounds,” said Joanna M. Shepherd, a law professor at Emory with a doctorate in economics who wrote or contributed to several studies. “But I do believe that people respond to incentives.”

But not everyone agrees that potential murderers know enough or can think clearly enough to make rational calculations. And the chances of being caught, convicted, sentenced to death and executed are in any event quite remote. Only about one in 300 homicides results in an execution. “I honestly think it’s a distraction,” Professor Wolfers said. “The debate here is over whether we kill 60 guys or not. The food stamps program is much more important.” There is also a classic economics question lurking in the background, Professor Wolfers said. “Capital punishment is very expensive,” he said, “so if you choose to spend money on capital punishment you are choosing not to spend it somewhere else, like policing.” A single capital litigation can cost more than $1 million. It is at least possible that devoting that money to crime prevention would prevent more murders than whatever number, if any, an execution would deter.

The available data is thin, mostly because there are so few executions. It seems unlikely,” Professor Donohue and Professor Wolfers concluded in their Stanford article, “that any study based only on recent U.S. data can find a reliable link between homicide and execution rates.” The two professors offered one particularly compelling comparison. Canada has executed no one since 1962. Yet the murder rates in the United States and Canada have moved in close parallel since then, including before, during and after the four-year death penalty moratorium in the United States in the 1970s.

“Deterrence cannot be achieved with a half-hearted execution program,” Professor Shepherd of Emory wrote in the Michigan Law Review in 2005. She found a deterrent effect in only those states that executed at least nine people between 1977 and 1996. Professor Wolfers said the answer to the question of whether the death penalty deterred was “not unknowable in the abstract,” given enough data. “If I was allowed 1,000 executions and 1,000 exonerations, and I was allowed to do it in a random, focused way,” he said, “I could probably give you an answer.”

Is the death penalty a deterrent?

Posted November 18, 2007