On climate and conflict: Precipitation decline and communal conflict in Ethiopia and Kenya

This study exploits a sudden and abrupt decline in precipitation of the long rains season in the Horn of Africa to analyze the possible link between climate change and violent armed conflict. Following the 1998 El Ni？o there has been an overall reduction in precipitation levels – associated with sea-surface temperature changes in the Indian and Pacific Oceans – resulting in an increase in the number and severity of droughts. Given that the probable cause of this shift is anthropogenic forcing, it provides a unique opportunity to study the effect of climate change on society compared to statistical inference based on weather variation. Focusing on communal conflict in Ethiopia and Kenya between 1999 and 2014, exploiting cross-sectional variation across districts, the regression analysis links the precipitation decline to an additional 1.3 conflict events per district. The main estimates show that there is a negative correlation between precipitation and communal conflict with a probability of 0.90. Changing model specification to consider plausible alternative models and accommodate other identifying assumptions produces broadly similar results. The generaliziability of the link between precipitation decline and conflict breaks down when using out-of-sample cross-validation to test the external validity. A leave-one-out cross-validation exercise shows that accounting for climate contributes relatively little to improving the predictive performance of the model. This suggests that there are other more salient factors underlying communal violence in Ethiopia and Kenya. As such, in this case the link between climate and conflict should not be overstated