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Monday, June 11, 2007

Studies: Death Penalty IS Effective

Sorry, Charlie. (And others.) It seems that every recent comprehensive study has shown that the death penalty does in fact have a strong effect on cutting down on homicides, with the only question being how many lives it saves:
They count between three and 18 lives that would be saved by the execution of each convicted killer. ...

"Science does really draw a conclusion. It did. There is no question about it," said Naci Mocan, an economics professor at the University of Colorado at Denver. "The conclusion is there is a deterrent effect."

A 2003 study he co-authored, and a 2006 study that re-examined the data, found that each execution results in five fewer homicides, and commuting a death sentence means five more homicides. "The results are robust, they don't really go away," he said. "I oppose the death penalty. But my results show that the death penalty (deters) — what am I going to do, hide them?

Personally, I think I'd be in favor of the death penalty even if it were only a question of one life being saved by it; I see no reason to spare convicted murderers' lives and have absolutely no sympathy for them. That DNA and other evidence is overturning convictions is wonderful, but I think that because we now have that technology we'll have fewer and fewer mistakes in the first place, so this will no longer be an issue. I may be biased in that I don't see how it's possible that it wouldn't deter crime; not only is it less likely to have idiotic releases of criminals (the infamous Illinois release is estimated to have cost 150 lives in the just six years since it happened), but [for example] criminals who already would be getting 25 to life if caught would have no disincentive to stop them from killing a person if they felt that person was a threat.

Regardless of my personal beliefs, though, it seems that there is a clear benefit to having the death penalty. People seem to forget that this does not mean it is required to be meted out; but I think that particularly for the obvious and more gruesome cases, the option must always be available. More importantly, this is a policy that will only negatively impact a tiny population - convicted murderers who have lost all their appeals - while saving the lives of innocent people. I don't understand how people aren't jumping at such an opportunity.

5 comments:

  1. Doesn't seem settled:

    Critics of the findings have been vociferous.

    Some claim that the pro-deterrent studies made profound mistakes in their methodology, so their results are untrustworthy. Another critic argues that the studies wrongly count all homicides, rather than just those homicides where a conviction could bring the death penalty. And several argue that there are simply too few executions each year in the United States to make a judgment.

    "We just don't have enough data to say anything," said Justin Wolfers, an economist at the Wharton School of Business who last year co-authored a sweeping critique of several studies, and said they were "flimsy" and appeared in "second-tier journals."

    "This isn't left vs. right. This is a nerdy statistician saying it's too hard to tell," Wolfers said. "Within the advocacy community and legal scholars who are not as statistically adept, they will tell you it's still an open question. Among the small number of economists at leading universities whose bread and butter is statistical analysis, the argument is finished."


    It also doesn't make much intuitive sense -- what kind of potential murderer is rational enough to be deterred by the death penalty but not life in prison? Of course, if the data become even clearer and it turns out you're right, I would be convinced that it's a deterrant. It just seems unlikely to me right now.

    Also, a few things leap out as absurd:

    The Illinois moratorium on executions in 2000 led to 150 additional homicides over four years following, according to a 2006 study by professors at the University of Houston.

    How could data possibly show causality there?

    If the death penalty does turn out to be a significant deterrent, I might change my mind about it. I'm not yet convinced, though.

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  2. I read the whole article as well. I don't buy those critics - there's little substantiation to what they're saying.

    Some claim that the pro-deterrent studies made profound mistakes in their methodology, so their results are untrustworthy.

    Such as what? The basic parameters outlined in the article sound decent, and they discounted or factored in almost anything I'd think of that would have a strong effect.

    Another critic argues that the studies wrongly count all homicides, rather than just those homicides where a conviction could bring the death penalty.

    I'd like a clearer explanation of what that means, but it seemingly assumes that a murderer is differentiating between the two when committing the crime, which is doubtful. I'm guessing that while they might factor "hey, I can die if I kill a guy" more than "well, let's see how I can go about this".

    And several argue that there are simply too few executions each year in the United States to make a judgment.

    Certainly possible, but that would go both ways. I'd err on the side of 'reduces homicides' when it comes to convicted murderers.

    what kind of potential murderer is rational enough to be deterred by the death penalty but not life in prison?

    What do you mean? If a guy commits other crimes? If he's already in the process of (say) a bank theft, and is already getting life if he gets caught?

    Unless you mean that both are equally bad, but I think that the human mind generally wants to stay alive - even in jail - rather than die. [At least until they actually are serving said life sentence.]

    How could data possibly show causality there?

    I could guess:

    1) If the released themselves killed people.
    2) People felt that they could get away with murder (literally), so those who might have otherwise second-guessed would now not.

    In truth, you're questioning causality in general and whether the person thinks about it before carrying out a murder, but that's true of the question in the first place. The point of my example in the post is to show exactly that: Not so much that a person thinks "well, is it worth getting killed" but more of a "well, I don't lose anything by killing the guy, but I have a lot to gain (getting away, revenge, et al)."

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  3. 'Freakonomics' by Michael Levitt deals with the issue of the death penatly as a deterrant. He basically says that there is no substantial evidence to show that the death penatly is enough of a detterant to lower the murder rate. The system just doesnt handle the death penatly in a way that will stick in the potential murderer's mind. You go through an appeal system, sit on death row for a bunch of years....etc.
    Im obviously summarizing what they say, but you should read the article.

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  4. A reasonable assumption would be that these studies took that into account.

    I love Freakonomics, but that doesn't mean that every argument they give is correct.

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  5. There's still a few problems.

    1. For the death penalty to even be worth considering there has to be a net gain in innocent lives saved. If it saves one life through deterrence at the expense of two innocent people sentenced to death then it's a bad policy. Even with DNA testing a person who didn't commit the crime could have their DNA at the scene of the crime. Even in cases of rape, the victim could've had consentual sex and then later been raped and both samples of DNA would be found or they could've had consentual sex and then been murdered without being raped by somebody else and they find the DNA and assume they were raped and murdered.

    2. I also have a problem with the process. After conviction, when determining whether to sentence someone to death the question of innocence is not considered. I think that at the very least the jury should have to find the defendant guilty with absolute certainty (i.e. even a longshot but barely possible, unreasonable doubt would spare them the death penalty) before sentencing to death. I still doubt that even with this guideline we'd be able to eliminate human error since people can think they are absolutely certain and be wrong but it would be an improvement. Currently this stage of the trial involves only the jury deciding if the convict has redeeming qualities and not if they're absolutely certain the person is guilty.

    3. What do I know. I haven't spent hours pouring over these statistics and I'm not going to pretend that I have. Some say it's proof of deterrence. Others say there are flaws in the study. Sure maybe the guy who ran this study was anti-death penalty but that doesn't prove it's correct. Mistakes can made regardless of what views a person holds. And I probably won't waste me time figuring this out unless I become a politician or if it's suddenly a major election issue and I want to make an informed vote.

    4. As for a murderer not being rational enough to be deterred by the death penalty over life imprisonment I'd say that a rational person would be MORE deterred by life imprisonment than the death penalty.

    5. This seems greatly relevant now, but politics and everything will be changed forever when nanotechnology creates indefinite lifespans (coming very soon, look it up). Then we could literally recreate h-ll for murderers by torturing them in prison forever and keeping them alive. Not saying I support this, but I think a lot of former pro-death penalty people will start supporting that and maybe even a few anti-death penalty people. Other people will support eternal punishment but not that severe. Still others would see eternity in prison as cruel and unusual and want to cap all prison sentences.

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