What Do Panel Studies Tell Us About a Deterrent Effect of Capital Punishment? A Critique of the Literature

• Activity Number: 187
• Type: Contributed
• Date/Time: Monday, July 30, 2012 : 10:30 AM to 12:20 PM
• Sponsor: Social Statistics Section
• Author(s): Amelia Haviland*+ and Aaron Chalfin and Steven Raphael
• Companies: Carnegie Mellon University and University of California at Berkeley and University of California at Berkeley
• Keywords: panel regression ; model uncertainty ; outliers ; death penalty ; deterrence

Abstract

In a paper commissioned by the NRC Panel on Deterrence and the Death Penalty, we provide a critical review of empirical research on the deterrent effect of capital punishment that makes use of panel data. Our review finds the connection between the theoretical reasoning underlying general deterrence and the regression models specified to be tenuous. Many of the papers purporting to find strong effects of the death penalty on state-level murder rates suffer from basic methodological problems: weak instruments, questionable exclusion restrictions, failure to control for obvious factors, and incorrect calculation of standard errors which in turn has led to faulty statistical inference. The lack of variation in the key underlying explanatory variables and the heavy influence exerted by a few observations is a fundamental problem contributing to overwhelming model uncertainty. We find the recent panel literature on whether there is a deterrent effect of the death penalty to be inconclusive as a whole and in many cases uninformative.