in: Oxford Research Encyclopedia of Politics
Regional integration theory seeks to explain the establishment and development of regional international organizations. Key questions are why and under which conditions states decide to transfer political authority to regional organizations; how regional organizations expand their tasks, competencies, and members; and what impact they have on states and societies in their regions. Whereas regional integration theory started with a broad comparative regional and organizational scope in the 1950s and 1960s, it has since focused on European integration and the European Union.The main (families of) theories explaining the development of European integration—rather than decision making and policy making in the EU—are intergovernmentalism, neofunctionalism, and postfunctionalism. The key debates in regional integration theory have taken place between variants of intergovernmentalist and neofunctionalist integration theory. Intergovernmentalism assumes national governments to be the key actors in regional integration. Governments use regional integration to maximize their national security and economic interests in the context of regional interdependence. Integration outcomes result from intergovernmental bargaining and reflect the regional preference and power constellations. Governments delegate authority to regional organizations to secure their bargaining outcomes but remain in control of regional organizations and the integration process. By contrast, neofunctionalism disputes that governments are able to control the integration process. Transnational corporations and interest groups as well as supranational actors are empowered by the integration process and shape it in their own interest. In addition, integration creates a variety of "spillovers" and path-dependencies that push integration beyond the intergovernmental bargain. More recently, postfunctionalism has enriched and challenged the theoretical debate on regional integration. In contrast to neofunctionalism, postfunctionalism assumes a backlash mechanism of integration. As regional integration progresses and undermines national sovereignty and community, it creates economic and cultural losers who are mobilized by integration-skeptic parties. Identity-based and populist mass politicization constrains regional integration and may even cause disintegration.Regional integration theories have closely followed and adapted themselves to the development of European integration. They cover the establishment and progress of supranational policies and institutions but also the recent crisis of the EU. An exemplary review of their explanations of major development in European integration shows that they are more complementary than competing.