The deterrent effect of capital punishment: Evidence from a "judicial experiment"

We use panel data for 50 states during the 1960-2000 period to examine the deterrent effect of capital punishment, using the moratorium as a 'judicial experiment." We compare murder rates immediately before and after changes W states' death penalty laws, drawing on cross-state variations in the timing and duration of the moratorium. The regression analysis supplementing the before and-after comparisons disentangles the effect of lifting the moratorium on murder from the effect of actual executions on murder. Results suggest that capital punishment has a deterrent effect, and that executions have a distinct effect which compounds the deterrent effect of merely (refinstating the death penalty, The finding is robust across 96 regression models.