Before the public conversation about the death penalty was all about money, and before the legal conversation was all about chemicals and devices, before the emergence of innocence projects, research tried to determine whether the death penalty deterred people from committing homicides. This was the first in a series of different discourses about the pros and cons of capital punishment.
As I explained in an earlier post, the first research project of this kind, Isaac Ehrlich's study from the 1970s, was seminal in bringing back the death penalty in 1976 after a four-year moratorium. Ehrlich found that each execution, on average, prevented eight homicides from occurring.
Throughout the years, the discussion about deterrence was relegated to a bitter feud between two research teams. In 2008, I had a chance to see a confrontation between those teams, and I wrote:
Everyone in the room was allowed to take a peek into the world of econometric studies of the death penalty, and to witness a cross between a genuine debate on the meaning of methodology and replication, and somewhat of an academic three-ring circus. As many readers may know, Ehrlich's work in the 1970s was cited in Gregg v. Georgia, leading to a reinstatement of the death penalty after a four-year moratorium; studies following Ehrlich's work have claimed to discredit their findings. The new generation of feuding parties includes Hashem Dezhbakhsh and Paul Rubin, who argue that their work confirms the deterrence effects of the death penalty, and Justin Wolfers (who was the discussant!), whose replication aims at discrediting the findings. Lots of good points were made. There are legitimate questions of what constitutes a faithful replication of a study; also, there's a respectable debate on the merits of controlling for certain variables and the purpose of including, or excluding, Texas from the analysis. In addition, we all got, for the price of admission, a healthy dosage of mud slinging, including critique over who chose to publish at a peer-reviewed publication and who didn't, and public exposure of the email exchange that preceded the conference. Afterwards, the two factions exited the room and went to lunch, leaving me to dig into my grilled veggie wrap and ponder other dimensions of the debate, namely, how we should improve dialogue across disciplinary boundaries, and how I wish someone studied the ideological aspect of all this, namely, whether in this sort of debate (or in the gun control/deterrence debate) methodological disagreements scrupulously follow political party lines.
My pal Dave Hoffman thought Wolfers and the dissenters won and wrote a thoughtful blog post about it.
A New York Times opinion piece is citing a National Research Council report, which once again tackles the issue of deterrence. The abstract provides in part:
This new report from the Committee on Law and Justice concludes that research to date on the effect of capital punishment on homicide rates is not useful in determining whether the death penalty increases, decreases, or has no effect on these rates. The key question is whether capital punishment is less or more effective as a deterrent than alternative punishments, such as a life sentence without the possibility of parole. Yet none of the research that has been done accounted for the possible effect of noncapital punishments on homicide rates. The report recommends new avenues of research that may provide broader insight into any deterrent effects from both capital and noncapital punishments.
This is an interesting addition to the discussion. It seemed to me that the deterrence argument became stale somewhere in the 1980s and remained of interest to a small number of researchers, whose ideological interest in the substance was secondary to their econometric methods. But this NRC report may be the last nail in the deterrence argument coffin.
It also speaks directly to the way SAFE California has been framing its campaign. The website is very careful, you'll notice, to avoid the words "abolition" and "end"; it does not make humanitarian arguments; rather, it speaks of "replacing" the death penalty with life without parole. I realize this is a political necessity, as not all people on board with the abolition agenda are bleeding-heart rehabilitation enthusiasts (SAFE California has victims and law enforcers on board.) But what I want to point out is that this is not merely a conversation about what needs to go away, but also about what will come in its place. It's impossible to have a conversation about the death penalty that is not comparative.
Many years after we do the right thing, we will need to have the conversation that European industrialized countries had a long time ago, about the merits of life without parole. By then, coalitions and priorities might shift. But, as Aragorn would say, while that day will inevitably come, it is not this day.