Duration ≠ Seriousness of Commitment: An Empirical and Theoretical Critique of Nyarko's Treaties vs. Executive Agreements

Abstract

In “Giving the Treaty a Purpose,” Julian Nyarko distinguishes between treaties and executive agreements and argues that treaties signal a higher level of commitment to our partners in cooperation than do executive agreements because treaties are more durable. Nyarko uses survival-time analysis to demonstrate that treaties last longer than executive agreements—that is, treaties are less likely to drop out of the Treaties in Force (TIF) series in any given year. The longer life of treaties is Nyarko's proxy for their greater durability. Nyarko argues that his result holds “even after controlling for a number of covariates that could influence the durability of the agreement,” like particular presidents, subject areas, and partner countries as well as the degree of divided government. Nonetheless, Nyarko's list omits the most important variable affecting durability as he defines it: intended duration. Sometimes the intended duration of a piece of formal international law is finite. Indeed, as I will explain in this response, under certain (and common) conditions, this choice of a finite duration is what makes the commitment credible (or, in Nyarko's language, reliable).