"Does improved communication as provided by modern cell phone technology affect the production of violence during insurgencies? Theoretical predictions are ambiguous, introducing cell phones can enhance insurgent communications but can also make it easier for the population to share information with counterinsurgents and creates passive signals intelligence collection opportunities. We provide the first systematic test of the effect of cell phone communication on conflict using data on Iraq’s cell phone network 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." (Abstract)