The resulting European economic integration, consisting, among other factors, in relatively free markets that facilitated the bridging of labour shortages through migration from Portugal, as well as other southern European countries (such as Italy, Spain or Greece,) towards Central Europe (e.g. Germany) – so-called 'Gastarbeiter' – initiated and strengthened the impressive European economic growth that also affected Portugal. Moreover, capital shortages did not affect economies as negatively as earlier since capital could be moved across borders more easily. In the following year, Portugal also became a member of the General Agreement on Tariffs and Trade (GATT), the International Monetary Fund, and the World Bank.