Measuring International Order: Three Approaches to an Amorphous Concept

The concept of international order is enjoying a renaissance among academic researchers, but two problems impede the development of this promising area of research. First, the term is used in vastly different ways, often without clear definition, lending it more talismanic than analytical value. Researchers talk past each other, hindering a cumulative research program. Second, where the term is used in a clearly defined way, researchers generally lack the data necessary to test statistical hypotheses about how orders form, change, and affect key outcomes of interest. This article addresses both problems by outlining three of the most common definitions of international order, explaining their logic, and generating new quantitative measures for the post-World War II period. We do not privilege a particular ontological conception of order as more correct than the others or prejudge the effect of international order on outcomes in international relations. Rather than making theoretical or causal claims, this paper quantifies common usages of “international order” in order to catalyze a more robust scientific research program on this important concept.