The Morality of Capital Punishment

The US is often criticized for its refusal to abolish capital punishment. Many now claim that abolition of capital punishment is a precondition of a civilized criminal-law system. Nobel laureate Gary Becker disagrees.

European governments are adamantly opposed to capital punishment – the European Union bans it outright – and some Europeans consider its use in the United States barbaric. Indeed, many European intellectuals argue that not just capital punishment, but punishment in general, does not deter criminals.

But, whereas Europeans, with crime rates well below American rates for the past half-century, could long afford to be relatively “soft” on most crimes, they have seen their crime rates increase sharply during the past twenty years. By contrast, American rates have fallen, in part because of greater use of punishment.

This includes capital punishment. I support executing some people convicted of murder because – and only because – I believe that it deters other murders. If I did not believe that, I would oppose capital punishment, because revenge and other possible motives should not be a basis for public policy.

Serious empirical research on capital punishment in the US began with a pioneering study by Isaac Ehrlich, published in 1975 in the American Economic Review. Some subsequent studies have sometimes found a much weaker deterrent effect, while others have found a much stronger effect. The available data are quite limited, however, so one should not base any conclusions solely on the econometric evidence.

Of course, public policy on any punishment cannot wait until the evidence is perfect. But, even with the limited quantitative evidence available, there are good reasons to believe that capital punishment deters.

Most people, and murderers in particular, fear death, especially when it follows swiftly and with considerable certainty following the commission of a murder. As David Hume put it in discussing suicide, “no man ever threw away life, while it was worth living. For such is our natural horror of death…” Likewise, Schopenhauer believed that “as soon as the terrors of life reach a point at which they outweigh the terrors of death, a man will put an end to his life. But the terrors of death offer considerable resistance…”

Opponents of capital punishment frequently proclaim that the state has no moral right to take anyone’s life, including that of the most reprehensible murderer. Yet that is absolutely the wrong conclusion for anyone who believes that capital punishment deters.

To see why, suppose that for each murderer executed (instead of, say, receiving life imprisonment), the number of murders is reduced by three, which is a much lower number than Ehrlich’s and some other estimates of the deterrent effect. This implies that for each murderer not executed, three innocent victims would die. In fact, the government would indirectly be “taking” many lives if it did not use capital punishment.

Saving three innocent lives for every person executed seems like a very attractive trade-off, and even two lives saved per execution seems like a persuasive benefit-cost ratio for capital punishment. Admittedly, however, the argument in favor of capital punishment becomes less clear-cut as the number of lives saved per execution falls. But, even if only one life were saved per execution, the tradeoff might still be desirable if the life saved is much better than the life taken, which would usually be the case.

Many people object to comparing the quality of the life spared and the life taken. Yet I do not see how to avoid such a comparison. Consider a career criminal who robs and kills a victim who led a decent life and left several children and a spouse behind. Suppose it would be possible to save the life of an innocent victim by executing such a criminal. To me it is obvious that saving such a victim’s life must count for more than taking the criminal’s life. Obviously, not all cases are so unambiguous, but a comparison of the qualities of individual lives must be part of any reasonable social policy.

This helps explain why capital punishment should be used only for murders, and not for lesser crimes. When the tradeoff is between taking lives and, say, reducing property theft, the case for milder punishments is far stronger. Although severe assaults, including some gruesome rapes, may approach some murders in severity, and might conceivably call for capital punishment, I do not support its use in these cases.

A powerful argument for reserving capital punishment for murders is “marginal deterrence.” If assault were punished with execution, perpetrators would have an incentive to kill their victims to avoid discovery (which is a major reason why the severity of punishments more generally should be matched to the severity of crimes).

One complication is that capital punishment may make a murderer fight harder to avoid being captured, which could lead to more deaths. But, while marginal deterrence is important, I believe the resistance of murderers to being captured, possibly at the expense of their own lives, is really indirect evidence that criminals do fear capital punishment.

Of course, I worry about the risk of executing the innocent. My support for capital punishment would weaken greatly if the rate of killing innocent people were as large as that claimed by many. However, I believe that the appeal process in the US offers enormous protection, not so much against wrongful conviction as against wrongful execution, so that there are very few, if any, documented cases of innocent people being killed. And this process has been strengthened enormously with the development of DNA identification.

Again, the debate about capital punishment is essentially a debate about deterrence (which may be reduced by lengthy appeals). I can understand that some people are skeptical about the evidence, although I believe they are wrong about both that and the common sense of the issue. It is very disturbing to take someone’s life, even a murderer’s life, but sometimes highly unpleasant actions are necessary to prevent even worse behavior that takes the lives of innocent victims.