Whether the death penalty is itself cruel and unusual punishment is another question, but the idea that the death penalty is a successful deterrent is, though perhaps the most often-cited reason for the usefulness of capital punishment, simply a fallacy. The fact is, there is to this day no study that we can reliably count on for evidence of deterrence. There are simply too many variables involved to make an accurate statistical connection between the death penalty and crime rates, not to mention that statistical correlation does not entail causation.
The most recent product of these failings is a study that was featured in the Wall Street Journal, written by two professors of
Adler and Summers’s study is alarming for the following reason: while they admit that there are likely other variables to be considered in this analysis (some I might propose are the availability of law enforcement personnel, public access to weapons, the presence of violence in media such as television and music, and access to education and health services), they suggest that, I quote, “such [variables] might exist, but until [they] can be identified, Occam's razor suggests the simplest solution is probably the actual solution.” (Adler and Summers) This is a highly disturbing thing for two professors who commonly use statistical analyses to say; indeed, not considering all the variables has been the downfall of many a statistical analysis; it is especially so in this case, in which the result we are examining, namely the number of murders in the U.S. every year, is affected by a plethora of things not even considered here.
Sadly, this faulty study received far more attention than it should have, including being lauded by former lawyer and current writer and popular talk show host Michael Smerconish, long a proponent of the death penalty and author of a recent pro-death penalty book. In an article he wrote in the November 11th issue of the Philadelphia Inquirer, he called the Adler and Summers study “stunning” and “bringing no agenda to the table” before he went on to express his disgust at the continuing appeals process of inmate Mumia Abu-Jamal (an issue he has discussed on his MSNBC show) and the Supreme Court’s de facto death-penalty moratorium.
Deterrence is also sometimes supported on the basis of non-statistical arguments. One of these is introduced by Ernest van den Haag, who makes the claim that while we don’t know for certain that the death penalty deters people from committing murder, we should “bet that it does,” on the following basis. If the death penalty does indeed deter and we use it, we save lives; if we don’t, we are leaving innocents to die. If it does not deter and we use it, we have “killed criminals;” if we don’t, we “come out ahead.” Van den Haag suggests it is therefore safer to have the death penalty. (Pojman 139-140) This “Best Bet” argument is troubling for at least two reasons: it assumes that some lives are more valuable than others, and that the use of the death penalty in itself is not a major moral issue. Jeffrey Reiman counters Van den Haag by explaining that anyone who commits a crime already faces a substantial risk of death from household weaponry and law enforcement personnel, and that it does not follow that the death penalty will deter more than any other form of punishment; this has not been studied. (144-145)
A similarly reasoned case is that of the commonsense argument of Louis Pojman, who accepts that there are too many variables to rely on statistics for judging deterrence, but recommends that we can by “common sense” deduce that: 1. What people fear most will have a greater deterrent effect on them, 2. People fear death more than any other punishment currently accepted by society, 3. therefore, the death penalty will deter more than any other accepted punishment. (141). Reiman again counters by suggesting that this makes two faulty assumptions – that there is an infinitely rising fear attached to punishment (rather than it leveling out), and that people make cost-benefit analyses before committing crimes. (146-147)
What, then, are death penalty advocates left with as a motive for keeping the death penalty as a punishment? Only vengeance. Though it is perhaps easy to empathize with the desire of families and friends of murder victims to “repay” those whom they believe have hurt them, it is far more difficult, practically and morally, to put this into effect. First, there is the issue of arresting the true culprit. The racial and class biases that continue to be inherent to the criminal justice system make this far more complicated than simply a matter of good forensics. Next, the idea of retributive justice itself need be reviewed – how do we come by the idea that the death penalty is proportional punishment for murder? Need punishment be proportional? Isn’t the use of death as punishment chosen arbitrarily? These questions remain unsolved, so it does not bode well for us to allow the use of a death penalty system in the meantime.
In review, we see that deterrence cannot be rightly be named a reason for having a death penalty, because there are no statistics to support it, and non-scientific arguments for it have failed. Deterrence continues to be referred to, however, because without it, there is only vengeance as a motive for execution.
Mappes, Thomas A, and Jane S Zembaty. Social Ethics: Morality and Social Policy. 7th ed.
Pojman, Louis P. “Deterrence and the Death Penalty.” Social Ethics: Morality and Social Policy. 1998. By Thomas A Mappes and Jane S Zembaty. 7th ed.
Reiman, Jeffrey. “Common Sense, the Deterrent Effect of the Death Penalty, and the Best Bet Argument.” Social Ethics: Morality and Social Policy. 1998. By Thomas A Mappes and Jane S Zembaty. 7th ed.
Smerconish, Michael. “Head Strong: But It Deters Future Killings, Study Says.”