SummaryIn this paper, we show that drought has a positive effect on the incidence of civil war over the period in Sub-Saharan Africa. We use the Palmer Drought Severity Index which is a richer measurement of drought than the measures used in the literature (rainfall and temperature) as it measures the accumulation of water in the soil in taking into account the temperature and the geological characteristics of the soil. We show that the risk of civil war increases by more than 42% from a "normal" climate to an "extremely drought" climate. Surprisingly, only 2.5% of this effect is channeled through economic growth. Keywords AbstractIn this paper, we show that drought has a positive effect on the incidence of civil war over the 1945-2005 period in Sub-Saharan Africa. We use the Palmer Drought Severity Index which is a richer measurement of drought than the measures used in the literature (rainfall and temperature) as it measures the accumulation of water in the soil in taking into account the temperature and the geological characteristics of the soil. We show that the risk of civil war increases by more than 42% from a "normal" climate to an "extremely drought" climate. Surprisingly, only 2.5% of this effect is channeled through economic growth.

This paper analyzes secession and group formation in the general model of contests due to Esteban and Ray (1999). This model encompasses as special cases rent seeking contests and policy conflicts, where agents lobby over the choice of a policy in a one-dimensional policy space. We show that in both models the grand coalition is the efficient coalition structure and agents are always better off in the grand coalition than in a contest among singletons. Individual agents (in the rent seeking contest) and extremists (in the policy conflict) only have an incentive to secede when they anticipate that their secession will not be followed by additional secessions. Incentives to secede are lower when agents cooperate inside groups. The grand coalition emerges as the unique subgame perfect equilibrium outcome of a sequential game of coalition formation in rent seeking contests. Copyright Springer-Verlag Berlin/Heidelberg 2006Secession, group formation, rent seeking contests, policy conflicts,

SummaryIn this paper, we show that drought has a positive effect on the incidence of civil war over the period in Sub-Saharan Africa. We use the Palmer Drought Severity Index which is a richer measurement of drought than the measures used in the literature (rainfall and temperature) as it measures the accumulation of water in the soil in taking into account the temperature and the geological characteristics of the soil. We show that the risk of civil war increases by more than 42% from a "normal" climate to an "extremely drought" climate. Surprisingly, only 2.5% of this effect is channeled through economic growth. Keywords AbstractIn this paper, we show that drought has a positive effect on the incidence of civil war over the 1945-2005 period in Sub-Saharan Africa. We use the Palmer Drought Severity Index which is a richer measurement of drought than the measures used in the literature (rainfall and temperature) as it measures the accumulation of water in the soil in taking into account the temperature and the geological characteristics of the soil. We show that the risk of civil war increases by more than 42% from a "normal" climate to an "extremely drought" climate. Surprisingly, only 2.5% of this effect is channeled through economic growth.

We investigate how variations in soil productivity affect civil conflicts. We first present a model with heterogeneous land in which variations in input prices (fertilizers) affect appropriable rents and the opportunity costs of fighting. The theory predicts that spikes in input prices increase the likelihood of conflicts through their effect on income and inequality, and that this effect is magnified when soil fertility is naturally more heterogeneous. We test these predictions using data on conflict events covering all Sub-Saharan African countries at a spatial resolution of 0.5 $\times$ 0.5 degree latitude and longitude over the 1997–2013 period. We combine information on soil characteristics and worldwide variations in fertilizer prices to identify local exogenous changes in input costs. As predicted, variations in soil productivity triggered by variations in fertilizer prices are positively associated with conflicts, especially in cells where land endowments are more heterogeneous. In addition, we find that the distribution of land fertility both within and across ethnic groups affects violence, and that the effect of between-group heterogeneity in soil quality is magnified in densely populated areas. Overall, our findings imply that inequality in access to fertile areas—an issue largely neglected in the literature dealing with the roots of Sub-Saharan African civil wars—constitutes a serious threat to peace at the local level.