Confounding social factors undermine cross-state and time-series deterrence studies

Evidence

Homicide rates were compared in neighboring states with and without capital punishment, such as Illinois, which at one point imposed the death penalty, and Michigan, which does not. The validity of this method depends on how well matched executing and nonexecuting states are for factors that affect murder rates. A second approach relies on time-series analyses. Societies impose, abolish, and reinstate the death penalty for capital crimes. Time-series data are analyzed to ascertain whether adoption of the death penalty reduces murder rates and whether its abolition is accompanied by a rise in murders. However, the interpretation of changes in murder rates over time is complicated by the fact that a host of social factors that can affect homicide rates change concurrently. This makes it difficult to disentangle the independent effects of a society’s death-penalty policy. — Albert Bandura, Moral Disengagement, 1945

Categorization

• DEFINE: A compact illustration of the identification problem in observational policy research.
• XREF: connects to: Simulation governs deterrence better than actual catastrophe does — Jean Baudrillard, Simulacra and Simulation, 190