Citation

Lewis E, Mohler G, Brantingham PJ, Bertozzi AL. Secur. J. 2012; 25(3): 244-264.

Copyright

(Copyright © 2012, Holtzbrinck Springer Nature Publishing Group -- Palgrave-Macmillan)

DOI

10.1057/sj.2011.21

PMID

unavailable

Abstract

Our goal in this article is to characterize temporal patterns of violent civilian deaths in Iraq. These patterns are expected to evolve on time-scales ranging from years to minutes as a result of changes in the security environment on equally varied time-scales. To assess the importance of multiple time-scales in evolving security threats, we develop a self-exciting point process model similar to that used in earthquake analysis. Here the rate of violent events is partitioned into a background rate and a foreground self-exciting component. Background rates are assumed to change on relatively long time-scales. Foreground self-excitation, in which events trigger an increase in the rate of violence, is assumed to be short-lived. We explore the model using data from Iraq Body Count on civilian deaths between 2003 and 2007. Our results indicate that self-excitation makes up as much as 37-50 per cent of all violent events and that self-excitation lasts at most between two and six weeks, depending upon the district in question. Appropriate security responses may benefit from taking these different time-scales of violence into consideration.

Keywords: modeling violence; point process; rational choice theory; routine activity theory; density estimation

Language: en