floating. The world interest rate can be exogenous or endogenous. The union countries may differ in money demand, consumption, imports, openness, or size. Previous versions of some parts were presented at the Annual Conference of the Gennan Economic Association and . at the Workshop on International Economics. I have benefited from comments by Christopher Bliss, Volker Clausen, Johannes Hackmann, Bernd Hayo, Jay H. Levin, Reinar Ludeke, Dirk Meyer, Jochen Michaelis, Franco Reither, Gerhard Rubel, WolfScMfer, Michael Schmid, Reinhard Selten, Hans- Werner Sinn, Sylvia Staudinger, Thomas Straubhaar, Bas van Aarle, and Artur Woll. In addition, Michael Brauninger and Michael Cyrus carefully discussed with me all parts of the manuscript. Last but not least, Doris Ehrich did the secretarial work as excellently as ever. I wish to thank all of them. Executive Summary 1) The monetary union as a whole. First consider fiscal policy.