Is the Phone Mightier Than the Sword? Cellphones and Insurgent Violence in Iraq

Jacob N. Shapiro and Nils B. Weidmann

Abstract

Does improved communication provided by modern cellphone technology affect the rise or fall of violence during insurgencies? A priori predictions are ambiguous; introducing cellphones can enhance insurgent communications but can also make it easier for the population to share information with counterinsurgents and creates opportunities for signals intelligence collection. We provide the first systematic micro-level test of the effect of cellphone communication on conflict using data on Iraq's cellphone network (2004–2009) and event data on violence. We show that increased mobile communications reduced insurgent violence in Iraq, both at the district level and for specific local coverage areas. The results provide support for models of insurgency that focus on noncombatants providing information as the key constraint on violent groups and highlight the fact that small changes in the transaction costs of cooperating with the government can have large macro effects on conflict.

Jacob N. Shapiro is Associate Professor of Politics and International Affairs at the Woodrow Wilson School at Princeton University, Princeton, New Jersey. He can be reached at jns@princeton.edu.

Nils B. Weidmann is Professor of Political Science in the Department of Politics and Public Administration at the University of Konstanz, Germany. He can be reached at nils.weidmann@uni-konstanz.de.

Footnotes

  The authors thank Zain Iraq for generously sharing data on their cellphone towers. Patson Anius, Walid Jallo, Alberto Lopez, Tijjay Majiyagbe, Lewis Shade, and Frederic Wohl provided critical insights into the construction of the Iraqi cellphone network. Our anonymous reviewers, the IO editorial team, and seminar participants at Colombia, Georgetown, Harvard, the Harris School, Michigan, Pennsylvania, Princeton, and Stanford Universities honed this article with their incisive comments. Our students and colleagues with operational experience in Afghanistan and Iraq provided valuable insights regarding mechanisms and many informative anecdotes. Josh Martin and Thomas Scherer provided fantastic research assistance throughout the project. Thanks to Josh Borkowski and Zeynep Bulutgil for conducting the coding of ethnic populations at the district level. This material is based on work supported by the Air Force Office of Scientific Research (AFOSR) under Award No. FA9550-09-1-0314, by the National Science Foundation (NSF) under Award No. CNS-0905086, by the Army Research Office (ARO) under Award No. W911NF-11-1-0036, and by the Alexander von Humboldt Foundation under a Sofja Kovalevskaja Award. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of AFOSR, United States Department of Defense, NSF, or ARO.