EconTech

In a policy debate, data is usually good. But it is important to put data in context. Before I rant:

“Does Death Penalty Save Lives? A New Debate”:

This is easy for me. It doesn’t matter whether the research on the issue is valid or not. I’m against the death penalty. Period.:

Does Death Penalty Save Lives? A New Debate, by Adam Liptak, NY Times: …According to roughly a dozen recent studies, executions save lives. For each inmate put to death, the studies say, 3 to 18 murders are prevented. The effect is most pronounced, according to some studies, in Texas and other states that execute condemned inmates relatively often and relatively quickly. The studies, performed by economists in the past decade, … say that murder rates tend to fall as executions rise. …

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. Critics of the studies say they are based on faulty premises, insufficient data and flawed methodologies.

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… “The existing evidence for deterrence,” they concluded, “is surprisingly fragile.”

Gary Becker, who won the Nobel Prize in economics in 1992 …, said the current empirical evidence was “certainly not decisive” because “we just don’t get enough variation to be confident we have isolated a deterrent effect.” But, Mr. Becker added, “the evidence of a variety of types — not simply the quantitative evidence — has been enough to convince me that capital punishment does deter and is worth using…”

…

Frankly, the case against these rather … reaching studies is much stronger than is made out. The sample size and confounding factors is similar to that for cross country analysis like that done in the political economy literature. It is very difficult to make any kind of strong statement with these types of datasets due to the inadequate variation. But why trust me, one of the best econometricians pretty much agrees:

“Creative” use of data by death penalty proponents

By Steven D. Levitt

The academic debate on the death penalty is heating up again. Three decades ago, Isaac Ehrlich went head to head with a dozen critics. In the end, most unbiased observers concluded that the results were too sensitive to minor changes in specifications to draw any strong conclusions.

More recently, a host of authors have once again been arguing that the death penalty is an effective homicide deterrent. For instance, in recent testimony in front of the U.S. Senate, economist Paul Rubin began his comments by saying, “Recent research on the relationship between capital punishment and homicide has created a consensus among most economists who have studied the issue that capital punishment deters murder.”

That struck me as a strange thing to argue given what I know about the situation.

I have a paper with Larry Katz and Ellen Shustorovich in 2003. We conclude that “…there is little systematic evidence that the execution rate influences crime ratese…” Of 20 different specifications we examine, in only three cases do we find a statistically significant reduction in homicide from the death penalty. In one case, we find a statistically significant increase. (In contrast to the findings on executions, we find that bad prison conditions do seem to reduce crime.)

Here is how Rubin describes my paper’s results in his testimony:

“Another recent paper by Lawrence Katz, Steven D. Levitt, and Ellen Shustorovich uses state-level panel data covering the period 1950 to 1990 to measure the relationship between prison conditions, capital punishment, and crime rates….In several estimations, both the prison death rate and the execution rate are found to have significant, negative relationships with murder rates…”

What about the other 17 specifications?

More damaging to the case in favor of a death penalty is an exhaustive new study by John Donohue (my co-author on the abortion-crime stuff) and Justin Wolfers (an economist at Wharton). In the paper, Donohue and Wolfers provide a devastating critique of the existing studies, including the ones cited by Rubin in his testimony.

Rubin’s testimony on the Donohue and Wolfers paper is as follows:

“A recent paper in the Stanford Law Review questions some of these studies. This paper purports to show that the estimates of a deterrent effect are “fragile” and can be changed by statistical manipulation. The results of this paper have not been evaluated by competent scholars; the Stanford Law Review, like all law reviews, is edited by students who have no particular competence in econometrics. Moreover, Professors Wolfers and Donohue chose not to make their paper available online through a service such as SSRN or the BE Press, so that the scholarly community did not have access to their analysis before it was published.”

While in the abstract I agree that it is preferable to publish work in peer reviewed journals, it is worth remembering that peer-review is nothing like a guarantee of quality. At best, one hopes that peer review culls out the truly bad research. But there are enough journals that all but the worst work can eventually be published in a peer reviewed journal. And when two top scholars like Donohue and Wolfers publish something, peer reviewed or not, it is worth taking note.

But, this is the kicker. If you have the patience to download a paper from the Social Science Research Network, click here and download this paper. If you compare Rubin’s testimony, you will find that in most parts it follows word for word what is in this paper (published, I should add, in a non peer reviewed journal).

Which wouldn’t be a big deal, except the paper that exactly matches Rubin’s testimony isn’t even written by Paul Rubin, it is written by his sometimes co-author Joanna Shepherd.

Of course, one way or the other, I don’t think the evidence is particularly germane to the valuations involved in making this decision (I suspect this is largely Thoma’s position, thus why he doesn’t care so much about the evidence). The state should not be involved in cold blooded murder of its citizens (or others for that matter). I find it hilariously (actually maddeningly, but if you don’t laugh, you have to start taking blood pressure medicine, plus I get alliteration with hilariously) hypocritical that conservatives, those haters of government, believing it to be everywhere incompetent, think it is capable of making appropriate decisions of how to go about committing cold blooded murder in a just manner. And of course, it doesn’t. Read any of the statistics on who receives the death penalty relative to those who don’t for similar cases, and you get an idea of the inequality in the system, along racial and wealth lines, at a minimum.

Of course, you can’t justly kill in cold blood, and that is the point. Once caught, the capital criminal is no longer a threat. To kill them, then, is to kill them in cold blood. It’s the same with killing POWs (though presumably they are not morally/legally culpable for their actions). The point remains the same though. When the threat is eliminated, killing is cold blooded murder.