A Preliminary Examination of the Prevalence and Correlates of Mass Casualty Terrorist Attacks

Thousands of terrorist attacks occur every year, but only a small fraction of them can be categorised as a mass-casualty terrorist (MCT) attack. Despite the fact that MCT attacks appear to be different from smaller-scale terrorist attacks (in terms of the implications it has for governments when it comes to prevention and response), both are lumped together in most analyses of terrorist attacks. This article discusses these differences and then proceeds to demonstrate how differences in the threshold used for MCT attacks lead to varied interpretations of its prevalence. The author then performs several exploratory analyses to show the correlates of MCT at both the country and group levels using the Global Terrorism Database, which contains information on terrorist events in over 100 countries from 1970-2020. The results regarding the circumstances under which MCT attacks matter are nuanced, with certain factors showing consistent results across both non-MCT and MCT attacks and others only mattering in one case or the other. Understanding the dynamics of MCT attacks is important for scholars, policymakers, and practitioners who must deal with this challenging problem.