The European Union (EU) is a political and economic union of 27 member states, located primarily in Europe. Committed to regional integration, the EU was established by the Treaty of Maastricht on 1 November 1993 upon the foundations of the pre-existing European Economic Community. With almost 500 million citizens, the EU combined generates an estimated 30% share (US$18.4 trillion in 2008) of the nominal gross world product