Why class inequality breeds coups but not civil wars

Does class inequality increase the risk of civil war? I posit that inequality between social classes affects civil wars through two pathways: (1) it heightens the risk of political violence by fueling distributive conflicts; and (2) it reduces structural coup-proofing, which, in turn, increases the capacity of the military to fight insurgents. Combining these effects implies that the net effect of class inequality on civil war is ambiguous. Although class inequality increases the propensity for violence, in unequal countries political violence rarely takes the form of wars because such countries have strong militaries. Class inequality, however, breeds other forms of political violence. In particular, it increases the likelihood of military coups. The two effects of class inequality reinforce each other in the case of coups: inequality simultaneously stirs distributional conflicts and increases the capacity of the military to mount coups by reducing coup-proofing. Using data on 128 developing countries between 1960 and 2008, I find that while class inequality fosters coups, it has no discernible effect on civil wars. I also provide evidence consistent with my causal mechanisms: (1) inequality creates greater threat to the rulers by fueling political instability; (2) inequality reduces structural coup-proofing; and (3) structural coup-proofing increases the likelihood of civil war.