Design, Inference, and the Strategic Logic of Suicide Terrorism

In “The Strategic Logic of Suicide Terrorism,” Robert Pape (2003) presents an analysis of his suicide terrorism data. He uses the data to draw inferences about how territorial occupation and religious extremism affect the decision of terrorist groups to use suicide tactics. We show that the data are incapable of supporting Pape's conclusions because he “samples on the dependent variable.”—The data only contain cases in which suicide terror is used. We construct bounds (Manski, 1995) on the quantities relevant to Pape's hypotheses and show exactly how little can be learned about the relevant statistical associations from the data produced by Pape's research design.