If you've been following world of capital punishment at all in the past few days, you already know what this post is about. The recent blizzard of articles in the US news media regarding some kind of revolutionary report (actually several studies) which examines the death penalty through the wonderfully empirical lens of economics has appeared with a force that's been shocking; I no longer have to search for articles on capital punishment lately. This whirlwind we've seen in the past three days was touched off by a November 17th front page article in the
New York Times which asks
Does the Death Penalty Save Lives? A New Debate. The article, and its
many,
many contemporaries (most of them re-reporting exactly what the
Times did, without a shred of additional analysis) are being said (by themselves) to have precipitated the first serious reexamination of the death penalty's deterrent effect "for the first time in a generation" (
New York Times).
If one reads the articles and their sometimes hysterical, sometimes jubilant quotes about this report which is, essentially, on the economics of murder, it seems as though the death penalty is of the most effective policemen in the country, "preventing 3 to 18 murders" for every inmate executed.
However, further examination and perhaps just a
shred of critical thinking reveal fundamental flaws in the conclusions drawn by the studies and espoused by their media entourage (an entourage eager to sell papers to a public which is equally eager to supplement its 70% support for the death penalty with some favorable articles). Step one is to actually
read one of the reports yourself - it's really not that long (the actual text is just over 20 double-spaced pages, followed by about 15 pages of pretty charts). Next, take a course in
elementary statistics, and pay particular attention to the lectures on sampling error and significance of standard deviations from the mean. Essentially, the data to construct a coherent, unimpeachable correlation and therefore argument are not present. As the
Times article notes:
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 in the Stanford Law Review in 2005.
Next, and perhaps most obviously, is the fact that the other facets of the death penalty are utterly unaffected by these studies: the issues of morality, of cost, of the message sent, are still just as pressing as they were last week. As a letter written to the New York Times the day after the piece ran says:
If the death penalty deterred killers, we would be able to find at least one, in a state without the death penalty, who expected to be caught and imprisoned for life but committed murder anyway. No rational person would make that exchange. Economists will keep debating the numbers, but they should support public policy that sends clear, rational messages. Here’s one: Killing people is wrong — whether they’re walking in a dark alley or strapped to a gurney.
Clearly, the moral and emotional issues are undiminished. These latest studies are interesting, and will serve to intensify the debate over capital punishment in the coming weeks and months. As we move forward with these new opinions, it's important to exercise discretion and critical analysis of how these numbers actually affect the debate.