Galvanized by the devastation of the Second World War, European countries achieved a historically unprecedented and unparalleled level of regional economic integration in the postwar period. Intensive cooperation between the two biggest powers of continental Western Europe, France, and Germany,...

I develop an index for economic integration accounting for its gradual and bilateral nature: the Gradual And Bilateral Integration (GABI) index. The graduality captures differences in the depth and path of five stages in economic integration and is an improvement over the use of binary dummy...