Monetary Policy in the European Monetary Systems (EMS) provides the reader with a critical assessment of the EMS operation, focusing on key issues like intervention in money and foreign exchange markets and credibility of EMS exchange rate bands. The book also reopens the discussion on the "EMS discipline-credibility hypothesis" and the notion of "New EMS", testing both with an original methodology. The conflict between internal and external objectives is made clear and the empirical results show the choices made by the individual countries and the resulting implications. The book is written with an empirical orientation based on a unifying data description framework.