The Democratic Peace through an Interaction of Domestic Institutions and Norms: Executive Constraints and Rule of Law

In an attempt to explain the democratic peace phenomenon, existing studies postulate institutional and normative models but treat them as contending and mutually exclusive explanations. This approach is both theoretically and empirically flawed. Extant institutional models fail to acknowledge that institutional factors have an impact only in the presence of requisite normative factors. Similarly, normative models fail to acknowledge that normative factors have the hypothesized impact only in combination with institutional factors. Since the possibility of such an interaction effect is overlooked, existing empirical models of the democratic peace are misspecified. This study fills the gap by introducing a multiplicative interaction model. This study presents evidence that, ceteris paribus, for democratic dyads in which the interaction effect of institutional and normative constraints is high, the likelihood of interstate disputes is lower than for nondemocratic dyads. Consequently, the democratic peace phenomenon should be seen primarily as an outcome of institutional and normative constraints working together.