Issue linkage and international cooperation: An empirical investigation

Abstract

Issue linkage—the simultaneous discussion of two or more issues for joint settlement—is a bargaining tactic that (1) increases the probability of states reaching a negotiated agreement and (2) motivates states to remain committed to an agreement. Unfortunately, beyond some suggestive case studies and a few indirect statistical tests, there exists no direct and systematic evidence to support either claim. To empirically identify the effect of issue linkage, one must overcome five difficulties: properly evaluating multilateral processes, identifying issue linkage, identifying failed negotiations, identifying enforcement problems, and accounting for missing linkage data. I address these limitations through a variety of new approaches, most notably a new unit of analysis (the k-ad) for analyzing multilateral events, new data on failed military alliance negotiations, and using “buffer states” to test the credibility of alliance commitments. I find that, for military alliance negotiations from 1860 to 1945, offers of trade cooperation provisions increase the probability of states reaching agreement and improve the credibility of those agreements. However, I also find that offers of trade cooperation do not have a positive effect on alliance negotiations from 1815 to 1859.