The geographical spillover of armed conflict in Sub-Saharan Africa

Anecdotal accounts of the geographical spread of war inevitably involve Sub-Saharan African (SSA) countries. But is conflict spillover effectively stronger in SSA than elsewhere? To answer this question, we estimate models of civil war onset comparing SSA against the rest of the world (RoW). We find that in SSA a neighbour at war increases the probability of civil war onset by at least 1%. This is not negligible, considering that the unconditional probability of civil war onset is 1.1% in the global sample and 1.5% in the SSA sample. The spillover effect in the RoW is three times smaller than in SSA and, in general, statistically not different from zero. The results are robust to changes in the definition of neighbourhood and the inclusion of regional variables in the estimating equations to account for clustering effects. Finally, we provide evidence that refugee inflows and the artificial separation of ethnic groups explain part, but not all, of the spillover effect in SSA.