Since the end of World War II, more than 16 million people have been killed in civil wars. For conflict prevention and intervention it is important to understand the causes of such conflicts. One of the core questions is why people join a deadly armed struggle. Economists suggest that individuals join if the personal gains are higher than the costs of participation. This cost–benefit calculus is referred to as being motivated by “greed.” Other social scientists and historians have emphasized that individuals join rebellions because of discrimination, oppression, and economic marginalization. Hence, the explanation of civil war participation is based on “grievance.” In the literature these greed-versus-grievance explanations have provoked an acrimonious debate. What has been commonly misunderstood is that greed and grievance are not ...