Author: Eric Posner and Alan Sykes

[Eric Posner is Kirkland & Ellis Distinguished Service Professor of Law and Aaron Director Research Scholar at the University of Chicago. Alan Sykes is Robert A. Kindler Professor of Law at NYU Law.] In Economic Foundations of International Law, we provide a treatise-like account of international law from a rational choice perspective. The book builds upon an already considerable body of work by many different authors, and we hope that it will stimulate further research in this area. We thank Andrew Guzman, Emilie Hafner-Burton, David Victor, Rachel Brewster, and Steve Charnovitz for taking the time to read the book and provide their reactions for this symposium, and Opinio Juris for hosting it. Here we provide a brief response to their comments. Hafner-Burton and Victor focus on the relationship between political science scholarship and legal scholarship, and see in an empirically grounded economic approach a way to reconcile the disparate focuses of the two disciplines, where in the past scholars in the two disciplines seemed to have trouble communicating with each other. We agree with their sentiments. Political scientists and law professors will always harbor different methodological orientations—political scientists, frankly, have higher standards both for modeling and empirical testing, while law professors are more preoccupied with interpreting legal texts and providing normative recommendations—but the rational choice framework provides a kind of portal between the two disciplines. Both groups understand the language of rational choice even if they find other theoretical constructs used by the other to be bewildering, and the rational choice framework provides a useful way to generate hypotheses for empirical testing. Hafner-Burton has herself been a leading figure in empirical testing of the effects of international human rights law, and although many law professors writing about human rights stubbornly refuse to engage with it, it is obvious that her work, the work of Beth Simmons, and that of other political scientists, will have a major effect on legal scholarship on human rights in the long run. By contrast, we question whether realist theory will ever have an impact on international law scholarship, and doubt that constructivism will ever have a distinctive impact on international law scholarship, though many of its premises and commitments mirror ways of thinking that have long played a role in legal scholarship of all types. Let us turn from positive to normative.