December 25, 2005

Further Comments on Capital Punishment-BECKER

Our discussion last week on capital punishment generated a lot of comments that are worth discussing in more detail. Since capital punishment is so controversial, we decided to continue the same subject this week.

First, let me correct a misunderstanding in some of the comments. I never claimed the evidence is anywhere near conclusive that capital punishment has an important deterrent effect. I stated that the evidence from quantitative studies is decidedly mixed, yet I concluded that "the preponderance of evidence does indicate that capital punishment deters". Although the weight of the positive evidence should not be overstated, the frequently stated claim that these studies prove that capital punishment does not deter is clearly false.

My belief in its deterrent effect is partly based on these limited quantitative studies, but also because I believe that most people have a powerful fear of death. David Hume said in discussing suicide that "no man ever threw away life, while it was worth living. For such is our natural horror of death…". Schopenhauer added also in discussing suicide "…as soon as the terrors of life reach a point at which they outweigh the terrors of death, a man will put a an end to his life. But the terrors of death offer considerable resistance…".

Nevertheless, the main point of my comment last week was not to try to prove that capital punishment deters murders, but rather to argue against the view that it is "immoral" for the State to take lives through capital punishment even if we assume that the deterrent effect on murders is sizeable. Indeed, I believe that deterrence can be the only reasonable basis for capital punishment. Revenge, retribution, and other arguments sometimes made to justify capital punishment are too subject to government abuse, and have been abused.

Some readers interpreted my views as implying that a major goal of government policy should in general be to save lives. That is not my belief. I am against governments interfering, for example, with the rights of people to overeat even when that causes obesity, disease, and possibly early death because overeaters are primarily "harming" themselves. In my view, people should have the right to do that.

Murder, on the other hand, involves taking the lives of others, and any reasonable discussion has to distinguish such behavior from individuals taking actions that affect only their own lives. In economists' language, murder involves the most severe negative externalities. If we assume for the sake of this discussion that there are two fewer murders for each murderer executed, the State would reduce two of these severe externalities for each murderer that it executes. This issue of the effect of capital punishment on innocent victims has to be confronted by even those most opposed to its use. And I frankly do not see how any reasonable and relevant philosophy could oppose the use of capital punishment under the assumptions of this example.

Admittedly, the argument gets less clear-cut as the number of lives saved per execution falls from two to lower values, say, for example, to one life saved per execution. In this case, I compared the qualities of the life saved and the life taken, to the dismay of some readers. In particular, I wrote that "wouldn’t the trade-off still be desirable if the life saved is much better than the life taken, which would usually be the case?" I do not see how to avoid making such a comparison. Consider a person with a long criminal record who holds up 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 the lives of such a victim has to count for more than taking the life of such a criminal. To be sure, not all cases are so clear-cut, but I am just trying to establish the principle that a comparison of the qualities of individual lives has to be part of any reasonable social policy.

This argument helps explain why capital punishment should only be used for some murders, and not for theft, robbery, and other lesser crimes. For then the trade off is between taking lives and reducing property theft, and the case in favor of milder punishments is strong. However, severe assaults, including some gruesome rapes, may approach in severity some murders, and might conceivably at times call for capital punishment, although I do not support its use in these cases.

A powerful argument for reserving capital punishment for murders is related to what is called marginal deterrence in the crime and punishment literature. If say perpetrators of assaults were punished with execution, an assaulter would have an incentive to kill the victims in order to reduce the likelihood that he would be discovered. That is a major reason more generally why the severity of punishments 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. That argument has to be weighed in judging the case for capital punishment. 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.

Some readers asked whether I also favor public executions of convicted murderers, mangling of their bodies, and other methods used in some countries still, and in most countries in the past? I do not because they seem unnecessarily abusive of convicted murderers without any compensating gains. However, I admit I would reconsider this position if it were demonstrated that such added punishments have a large effect in reducing the number of murders. For those who find such a position "barbaric", I would ask how many innocent victims are they willing to tolerate before they might take a more positive position on these additional punishments?

Of course I am worried about the risk of executing innocent persons for murders committed by others. In any policy toward crime, including capital punishment, one has to compare errors of wrongful conviction with errors of failing to convict guilty persons. My support for capital punishment would weaken greatly if the rate of killing innocent persons were as large as that claimed by many. However, I believe along with Posner that the appeal process offers enormous protection not against wrongful conviction but against wrongful execution. And this process has been strengthened enormously with the development of DNA identification. However, lengthy appeals delay the execution of guilty murderers, and that can only lower the deterrent effect of capital punishment.

So to summarize once again my position on this controversial question, I favor capital punishment because and only because I believe it has "sizeable" deterrent effects. I would join the anti-capital punishment side if this view turns out to be wrong, if it were proven that many innocent persons are wrongly executed, or if it is administered in such a racially biased manner as to wrongly convict many black persons, and to be little used against white murderers. But I do not believe that the available evidence strongly supports any of these arguments against the use of capital punishment.

Posted by Gary Becker at 11:51 PM | Comments (29) | TrackBack (0)

Further Comments on Capital Punishment--Posner

Becker has presented in his post today a compelling restatement of the economic case for capital punishment. I have a few minor disagreements and qualifications, and I will first mention them and then respond to some of the very large number of comments that my last week's posting elicited.

I do not consider revenge an impermissible ground for capital punishment. Revenge has very deep roots in the human psyche. As I have long argued, basing the argument on work by evolutionary psychologists such as Robert Trivers, the threat of revenge must have played an essential role in maintaining order in the "ancestral environment." That is a term that evolutionary biologists use to describe the prehistoric era in which human beings evolved to approximately their current biological state. In that era there were no laws, police, etc., so the indignation that would incite a person to revenge himself upon an aggressor must have had substantial survival value and become "hard wired" in our brains. The wiring remains, and explains some of the indignation that people feel, especially but not only the friends and family members of murder victims, toward the murderer. It seems plausible to me (here modifying what I said in my original posting) that the net increment in utility that they derive from the execution (versus life imprisonment) of the murderer exceeds the net increment in disutility that the murderer derives from being executed rather than imprisoned for life. The strong support for capital punishment in public opinion polls provides limited support for this conjecture.

I do not favor public executions; nor dismemberment or other horrific modes of execution. The incremental deterrent effect might well be nontrivial, but would be outweighed by public revulsion. There is also the danger of brutalization. As Friedrich Nietzsche pointed out, making people squeamish is one of the projects of modernity, and may explain the banning of blood sports as well as the movement away from public and gruesome executions. The idea is that if people become unaccustomed to bloody sights they will be less likely to employ violence in their relations with other people. Still another objection to public and gruesome executions is that they offer murderers an opportunity to die as heroes by showing fortitude.

I agree that marginal deterrence is important and that it generally argues for reserving the heaviest sentences for the most serious crimes. But there are two important qualifications. First, a very heavy sentence may be necessary to deter a minor crime because the likelihood of apprehension is very low. The expected punishment cost of crime is, as a first approximation (ignoring attitude toward risk), the punishment if imposed multiplied by the probability of imposition, so if the probability is very low a compensating increase in punishment is indicated. This does not impair marginal deterrence as long as the crimes are not close substitutes: a heavy fine for litterers will not increase the robbery rate, whereas capital punishment for robbers would increase the murder rate (of robbers' victims)--were it not for my second qualification. Even if murder and robbery were both capital crimes, there would be marginal deterrence because the police would search much harder for a robber who murdered his victim; the more extensive search would compensate, in part anyway, for the loss of the information that the victim could have given the police to identify the robber. Moreover, capital punishment is merely a ceiling; even if robbery were a capital crime, judges and juries would be much less likely to impose the death sentence on a robber who had not killed his victim than on one who had.

Marginal-deterrence theory provides, however, a compelling reason to execute prisoners sentenced to life without parole who murder in prison; the threat of a sentence of imprisonment can have no deterrent effect on them.

Becker mentions the possibility of racial discrimination in execution. Studies done some years ago--I do not know whether they would be descriptive of current practice--revealed the following pattern: murderers of black people were less likely to be executed than murderers of white people. Since blacks were more likely to murder other blacks than to murder whites, this meant that blacks were less rather than more likely to be executed than whites, relative to the respective murder rates of the two races. (Blacks commit murders at a much higher rate than whites.) The explanation offered was that judges and juries tended to set a lower value on black victims of murder than on white ones. From this some observers inferred that capital punishment discriminates against blacks. The inference is incorrect. The proper inference is that murderers of blacks are underpunished.

I turn now to the comments on my posting. A long comment by "ohwilleke" makes a number of interesting points, but they do not support his opposition to capital punishment. He notes first of all that many factors influence the murder rate besides the probability of execution. That is true, but it does not, as he suggests, make it "insanely difficult to make any econometric estimate" that is not "meaningless." Econometrics, which is to say the set of statistical methods used by economists to try to tease out causal factors, enables the particular factor of interest, in this case the probability of execution, to be isolated. The methods are not entirely reliable, which is why neither Becker nor I claim that economists have proved that capital punishment deters; we merely claim that there is significant evidence that it does. I note how many commenters remark correctly that murder rates are higher in the South, even though that is where most executions occur, than in other regions. But that is not an argument that executions do not deter. The higher the background rate of murder, the more severe one expects punishments to be. A high murder rate implies a high expected benefit from murder and so the expected cost of punsihment has to be jacked up to offset that greater benefit.

Ohwilleke's comment claims that the "error rate" in capital punishment is 10 percent. This is incorrect. Not a single person among the 119 that he contends were erroneously sentenced to death was executed. That is a zero error rate.

One commenter asks whether capital punishment "really deter[s] the type of person who actually does the murdering?" Of course if someone in a state that has capital punishment commits the kind of murder that puts him at risk of such punishment, the threat of capital punishment has not deterred. This is the usual situation with criminal punishment. People who commit crimes are people for whom the expected cost of punishment, combined with the other costs of crime, is less than the expected benefit of the crime. The purpose of punishing these people is not to deter them--by committing the crime in the face of threatened punishment they have shown themselves to be undeterrable--but to deter people who, were it not for the expected punishment cost, would commit the crime because its other costs were lower than its expected benefit.

Finally, several comments usefully point out that capital punishment has a secondary deterrent effect: it induces murderers to plead guilty and receive a life sentence.

Posted by Richard Posner at 09:42 PM | Comments (32) | TrackBack (0)

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