This book studies the interactions between monetary and fiscal poUcies in the euro area. It carefully discusses the process of policy competition and the structure of policy cooperation. As to policy competition, the focus is on competition between the European central bank, the American central bank, the German government, and the French government. As to policy cooperation, the focus is on the same institutions. These are higher-dimensional issues. The pohcy targets are price stability and full employment. The policy makers follow co- turkey or gradualist strategies. The policy decisions are taken sequentially or simultaneously. Monetary and fiscal policies have spillover effects. Special features of this book are numerical simulations of policy competition and numerical solutions to policy cooperation. The present book is part of a larger research project on European Monetary Union, see the references at the back of the book. Some parts of this project were presented at the World Congress of the International Economic Association. Other parts were presented at the International Conference on Macroeconomic Analysis, at the International Institute of Public Finance, at the Macro Study Group of the German Economic Association, at the Annual Meeting of the Austrian Economic Association, at the Gottingen Workshop on International Economics, at the Halle Workshop on Monetary Economics, at the Research Seminar on Macroeconomics in Freiburg, and at the Passau Workshop on International Economics.