Like many other fields of legal scholarship, international law has seen an explosion in empirical work in recent years. This development reflects the increasing influence of social science in legal scholarship, developments in political science and international relations theory, and the objective expansion in the importance and visibility of international law in the 1990s, as reflected in the scope and depth of international institutions.
In the case of international law, the earlier dearth in empirical work reflected, on the one hand, the enduring importance of the realist tradition in international relations scholarship. For classical realists, state power determined outcomes on the international play, and international law was “epiphenomenal,” without independent causal impact on outcomes. From the other end of the spectrum, traditional international legal scholarship focused on doctrinal and normative concerns. Such scholarship tended to assume rather than examine the efficacy of international law and cooperation, and was normative in character, bemoaning instances in which international legal institutions were unable to constrain power.
In contrast, the new empirical scholarship follows from the institutionalist tradition in political science, taking the reach and efficacy of international law as empirical questions, to be neither assumed (as in traditional doctrinal scholarship) nor explained away as unimportant (as in the realist tradition). In tackling these questions of scope and efficacy, scholars are using a wide variety of methodologies, both qualitative and quantitative, and examining a diverse array of questions in various substantive areas of international law.
Typically, research on international law ties into one or both of two broad overreaching questions:
■ How is international law produced; that is, who are the actors, what mechanisms and processes govern their interaction, and the shape of the resulting institutions?
■