Citation

Clauset A, Gleditsch KS. PLoS One 2012; 7(11): e48633.

Affiliation

Department of Computer Science, University of Colorado, Boulder, Colorado, United States of America ; BioFrontiers Institute, University of Colorado, Boulder, Colorado, United States of America ; Santa Fe Institute, Santa Fe, New Mexico, United States of America.

Copyright

(Copyright © 2012, Public Library of Science)

DOI

10.1371/journal.pone.0048633

PMID

23185267

Abstract

We identify robust statistical patterns in the frequency and severity of violent attacks by terrorist organizations as they grow and age. Using group-level static and dynamic analyses of terrorist events worldwide from 1968-2008 and a simulation model of organizational dynamics, we show that the production of violent events tends to accelerate with increasing size and experience. This coupling of frequency, experience and size arises from a fundamental positive feedback loop in which attacks lead to growth which leads to increased production of new attacks. In contrast, event severity is independent of both size and experience. Thus larger, more experienced organizations are more deadly because they attack more frequently, not because their attacks are more deadly, and large events are equally likely to come from large and small organizations. These results hold across political ideologies and time, suggesting that the frequency and severity of terrorism may be constrained by fundamental processes.

Language: en