Abstract
Although we live in a world of international regimes, the scholarly literature on them remains rudimentary, especially in analytic terms. This essay examines the proposition that all international regimes are social institutions, even though there is great variation among them. Among other things, this suggests that regimes are dependent upon the maintenance of convergent expectations among actors; formalization is not a necessary condition for the effective operation of regimes; and regimes are always created rather than discovered. A conceptual framework and a research agenda for the comparative study of international regimes, as laid out in this essay, would guide studies of specific regimes and improve our ability to reach general conclusions about this fundamental, yet poorly understood, international phenomenon.