Nonparametric Model Discrimination in International Relations

This study introduces a simple nonparametric test for the relative discrimination of models in international relations research. The common parametric approach, the Vuong test, does not perform well under the small-n, high canonical correlation conditions that are sometimes encountered in world politics research. The nonparametric approach outperforms the Vuong test in Monte Carlo experiments and is trivial to implement even for the most complicated models. The method is applied to two empirical examples: the debate over long cycles and the effect of domestic politics on foreign policy decision making.