Dyadic effects of democratization on international disputes

I explore the dyadic, as opposed to monadic, effect of democratizationon war. Using a simple repeated game of interstate interaction,I show that, as a state shifts towards democracy, its citizensaquire more opportunities and become more willing to removethose leaders that they expect will reduce their welfare. Rationalleaders anticipate this consequence, and their incentives tomaintain cooperative relationships with other democracies increaseas their states become democratic. The hypothesis drawn fromthe model predicts that democratization will have a pacifyingeffect in a dyadic relationship between democracies. Empiricaltesting is designed to isolate the dyadic effect from the monadicand to distinguish among competing hypotheses. The predictionsare tested with widely used data on political institutions andmilitarized interstate disputes. The result shows that democratizationindeed reduces the likelihood of waging war. However, this pacifyingeffect is largely attributed to the dyadic effect with a democraticopponent; the risk of war remains unchanged when facing a non-democraticopponent.