Neo-Functionalism

Neo-functionalism is a theory of regional integration developed primarily by Ernst B. Haas in his 1958 book The Uniting of Europe, which analyzed the European Coal and Steel Community (ECSC). Building on David Mitrany's earlier functionalist ideas, Haas and later scholars such as Leon Lindberg and Philippe Schmitter argued that integration is driven less by grand bargains between statesmen than by the everyday logic of interdependence among sectors, interest groups, and bureaucracies.

The theory rests on a few core mechanisms:

• Spillover: cooperation in one policy area (say, coal and steel) generates functional pressures to integrate related areas (energy, transport, competition policy) because the original arrangement cannot work in isolation. Haas distinguished functional spillover from political spillover, in which domestic interest groups shift their loyalties and lobbying toward the supranational level.
• Supranational entrepreneurship: institutions like the European Commission and the European Court of Justice actively cultivate further integration rather than passively executing member-state preferences.
• Elite socialization: national officials working in Brussels gradually adopt European frames of reference.

Neo-functionalism was the dominant lens for studying European integration in the 1950s and 1960s but lost ground after Charles de Gaulle's 1965 "empty chair" crisis and the 1966 Luxembourg Compromise, which reasserted member-state control. Haas himself called the theory "obsolescent" in 1975. It was partially revived after the Single European Act (1986) and the Maastricht Treaty (1992), and scholars like Wayne Sandholtz and Alec Stone Sweet reformulated it as "supranational governance."

The theory's main rival is liberal intergovernmentalism, associated with Andrew Moravcsik, which insists that major integrative steps reflect bargaining among member-state governments pursuing national preferences. Critics also note that neo-functionalism was tailored to the European case and travels poorly to ASEAN, Mercosur, or the African Union, where spillover has been limited.