Skip to content

Tag: policy analysis

The deterrent effect of the death penalty

Does the death penalty lead to a lower number of homicides? A recent paper by Charles Manski and John Pepper argues that, on the basis of existing US data, we do not know. Both positive and negative effects of the application of the death penalty are consistent with the observed homicide rates in the US. The argument itself is not new (see for example this 2006 paper by John J. Donohue III and Justin Wolfers) but Manski and Pepper’s text is still very interesting and highly instructive. Manski and Pepper strip the problem to the core. Say we only have four observation points – the average yearly homicide rates for ’75 and ’77 in two sets of states that either did (A) or (B) did not reinstate the death penalty after the moratorium was lifted with the 1976 Gregg decision. So in 1975 both sets of states did not have a death penalty while in 1977 group A had reinstated it. I reworked the table with the rates into the figure below. The red dots show the homicide rates in the ‘death penalty’ states and the blue ones in the remaining ones. The authors show that on the basis of these four numbers, there are at least three point estimates of the effect of the death penalty that we can derive from the data depending on the assumptions that we are willing to make. First, we can assume that the selection of individual states into the two groups (‘death penalty’…