Deterrence Versus Brutalization: Capital Punishment's Differing Impacts Among States

Abstract

This paper is the first study to establish that capital punishment's impact is different among U.S. states, deterring murders in some states, but actually increasing murders in many others. Studies by economists, including myself, have typically used large data sets of all 50 states or all U.S. counties to show that executions, on average, deter murders. In contrast, studies by sociologists, criminologists, and law professors often examine only one or a few jurisdictions and usually find no evidence of deterrence. Using a well-known data set and well-tested empirical methods, I find that the impact of executions differs substantially among the states. Executions deter murders in six states and have no effect on murders in eight states. In thirteen states, executions increase murders - what I call the "brutalization effect." In general, the states that have executed more than nine people in the last twenty years experience deterrence. In states that have not reached this threshold, executions generally increase murders or have no significant impact. On average across the U.S., executions deter crime because the states with deterrence execute many more people than do the states without it. The results of this paper help to explain the contrasting conclusions of earlier papers: whether deterrence exists depends on which states are examined. My results have three important policy implications. First, if deterrence is the objective, then capital punishment generally succeeds in the few states with many executions. Second, the many states with numbers of executions below the threshold may be executing people needlessly. Indeed, instead of deterring crime, the executions may be inducing additional murders: a rough total estimate is that, in the many states where executions induce murders rather than deter them, executions cause an additional 250 murders per year. Third, to achieve deterrence, states must generally execute many people. If a state is unwilling to establish such a large execution program, it should consider abandoning capital punishment.

Keywords: death penalty, deterrence, capital punishment

JEL Classification: K00, K14, K42, H00, C00, C33