Neofunctionalism is a theory of regional integration, builing on the work of Ernst B. Haas, an American political scientist. Jean Monnet's approach to European integration, which aimed at integrating individual sectors in hopes of achieving spill-over effects to further the process of integration, is said to have followed the neofunctional school's tack. Haas later declared the theory of neofunctionalism obsolete, after the process of European integration started stalling in the 1960s, when Charles de Gaulle's "empty chair" politics paralyzed the institutions of the European Coal and Steel Community, European Economic Community, and European Atomic Energy Community. Neofunctionalism has also been called too eurocentric and hence incapable of describing the process of integration in general.