While most quantitative studies find a negative relationship between economic interdependence and interstate disputes, research by Barbieri finds that interdependence precipitates conflict. Participants in the debate suggest several causes, but we show that alternative variable constructions are sufficient to account for the discrepant findings. A simple formal equivalence unites respective operationalizations of dyadic interdependence used by Oneal & Russett ( trade dependence, trade ij/GDP i) and Barbieri ( trade share, trade i/trade i) with the consensus construction of monadic trade openness (trade i/GDP i). We also show that Barbieri's trade share is negatively correlated with openness. Arguments in the article are verified through large-sample quantitative regression analyses of the two competing dyadic variable constructions and trade openness on MID onset. The results of these dyadic regression analyses show that trade share increases the probability of MID onset, trade dependence decreases the probability of MID onset and, correspondingly, that trade openness is negatively correlated with MID onset.