Capital Punishment and the Deterrence Hypothesis: Some New Insights and Empirical Evidence

Abstract

We argue that the deterrent effects of the certainty and severity of punishments on murder depend on the status of the death penalty. Legalizing the death penalty not only adds capital punishment as a deterrent but also increases the marginal productivity of other deterrence measures in reducing murder rates. From the econometric standpoint, this suggests that the structure of the murder supply function depends on the status of the death penalty, which is in itself endogenous. Consistent estimation of the deterrent effects of capital punishment and other preventive measures requires taking into account the endogenous nature of the status of the death penalty. Using switching regression techniques and a well-known US data set, we test the implications of the model. The empirical results are consistent with the theoretical predictions of the model and robust to alternative specifications. They also lend strong support to the deterrence hypothesis.

Keywords: capital punishment, deterrence hypothesis, death penalty law

JEL Classification: K42