The Paris summit in 1974 is most famous for having formally created the European Council, and numerous studies have debated whether this institutionalised summitry undermined the supranational nature of the Community. But existing studies have ignored a potentially significant element of the Paris summit that on its face unmistakably advances supranationalism: the commitment to renounce the informal practice in the Council of Ministers of making agreement on all questions conditional on unanimous consent. We evaluate whether this commitment had predictable effects on Commission and Council behaviour, using quantitative analysis and extensive process tracing to compare decision-making before and after the Paris summit. Our study has implications for research on informal governance as well as the history of European integration.
