Security Studies, Vol. 17, page(s): 107-137
This article investigates the determinants of armed group organization and the downstream effects of organization on civil wars. It demonstrates that the interaction between geographical and technological factors influences the types of hierarchical organizations that armed groups develop. It then argues that variations in the types of hierarchies developed by armed groups have important consequences for principal-agent relations, which in turn affect groups’ overall level of military effectiveness. Using evidence from field research conducted in Liberia and Sierra Leone, the model’s plausibility is examined in comparative case studies of four armed groups that fought in those countries from 1989–2003.