The Spatial Diffusion of Suicide Attacks

This paper studies the diffusion of suicide bombings as a tactic employed by terrorist groups from 1981 to 2008. The empirical strategy is motivated by the literature on the diffusion of innovation. Specifically, this paper builds on the literature on the diffusion of policies across states to develop hypotheses about the spread of suicide attacks across space and over time. We use data from the National Consortium for the Study of Terrorism and Responses to Terrorism (START) to evaluate hypotheses about the diffusion of suicide bombings. The results suggest a consistent and robust relationship between geography and the diffusion of suicide bombings. Successful suicide attacks appear to diffuse across borders and to increase over time.