This paper studies the incidence of civil war over time. We put forward a canonical model of civil war, which relates the incidence of conflict to circumstances, institutions and features of the underlying economy and polity. We use this model to derive testable predictions and to interpret the cross-sectional and times-series variations in civil conflict. Our most novel emprical finding is that higher world market prices of exported, as well as imported, commodities are strong and significant predictors of higher within-country incidence of civil war.
Besley, T.J.; Persson, T. The Incidence of Civil War: Theory and Evidence. (2008)