The consequences of internal displacement on civil war violence: Evidence from Syria

How do flows of internally displaced persons (IDPs) affect wartime violence? We argue that government and rebel forces respond to IDP flows in different ways, which condition where and when they employ violence. State responses are driven by the need to identify insurgents and their civilian supporters, and depend on how much information they have about where IDPs are coming from and where they are seeking to resettle. Rebel responses are driven by their need to monitor and control civilian movements, which leads to more violence against civilians in transit areas heavily trafficked by IDPs. Drawing on novel subnational data from Syria, we employ social network analysis to examine migration flow characteristics beyond aggregate IDP inflows and outflows. We find that the greater the local clustering of IDP flows ? i.e., the less complex and diverse displacement movements are ? the more pro-government combatants are able to detect IDPs? origins and destinations, and the higher the number of civilian killings. Transit locations, meanwhile, become epicenters of rebel violence against civilians. While scholars have found that more information about civilian behavior causes combatants to employ more selective violence, our results suggest that more information about displacement prompts more collective violence from governments. The findings also indicate that governments respond to IDP flows after movement, whereas rebels respond to IDP flows during movement. This underscores the importance of focusing on how armed groups respond to displacement flows in order to better understand the consequences of population movements in wartime.