The European integration has progressed rapidly in the last decade. The European Economic and Monetary Union (EMU) reached its final stage with the introduction of the euro in 1999, while the European Union (EU) enlarged in 2004 and 2007 to include Central and Eastern European Countries. Most of the incumbent EU members and some new ones have replaced their sovereign monetary policies with a supranational one, while fiscal policies remain a national affair. This book discusses welfare gains of fiscal cooperation and fiscal and monetary cooperation in the EU and EMU. Country-specific features, such as the size and ownership structure of the economies are taken into account to differentiate between the incumbent and new EU members. Furthermore, as all new EU members will have to join the euro area, welfare gains from joining the EMU are also discussed. The analysis should be of interest to economists and policymakers, as well as general public interested in European integration and economic policy.