Gradualism and uncertainty in international union formation: The European Community’s first enlargement

Abstract This paper introduces a new theoretical framework of international unions qua coalitions of countries adopting a common policy and common supranational institutions. I make use of a three-country spatial bargaining game of coalition formation, in order to examine the endogenous strategic considerations in the creation and enlargement of international unions. Why would we observe a gradualist approach in the formation of the grand coalition even if the latter is assumed to be weakly efficient? I propose asymmetric information about the benefits of integration as a mechanism that can generate gradual union formation in equilibrium. As it turns out, it may well be in the ‘core ’ countries ’ interest to delay the accession of a third, ‘peripheral ’ country in order to (1) stack the institutional make-up of the initial union in their favor and (2) signal their high resolve to wait out the expansion of their bilateral subunion. A related case from the European experience provides an interesting illustration