Risks of mortality and morbidity from worldwide terrorism: 1968-2004.

Worldwide data on terrorist incidents between 1968 and 2004 gathered by the RAND Corporation and the Oklahoma City National Memorial Institute for the Prevention of Terrorism (MIPT) were assessed for patterns and trends in morbidity/mortality. Adjusted data analyzed involve a total of 19,828 events, 7,401 "adverse" events (each causing >or= 1 victim), and 86,568 "casualties" (injuries), of which 25,408 were fatal. Most terror-related adverse events, casualties, and deaths involved bombs and guns. Weapon-specific patterns and terror-related risk levels in Israel (IS) have differed markedly from those of all other regions combined (OR). IS had a fatal fraction of casualties about half that of OR, but has experienced relatively constant lifetime terror-related casualty risks on the order of 0.5%--a level 2 to 3 orders of magnitude more than those experienced in OR that increased approximately 100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14% to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2.5% (or 10%) of harm-ranked events in OR (or IS). Extreme values of victim/event rates were approximated fairly well by generalized Pareto models (typically used to fit to data on forest fires, sea levels, earthquakes, etc.). These results were in turn used to forecast maximum OR- and IS-specific victims/event rates through 2080, illustrating empirically-based methods that could be applied to improve strategies to assess, prevent, and manage terror-related risks and consequences.