The Papers collected in this volume are those presented at the ninth Colloquium arranged by the Societe Universitaire Europeenne de Recherches Financi{~res (SUERF), which took place at Helsing¢r, Denmark, in October 1980. The Society is supported by a large number of central banks, commercial banks, ·and other fmancial and business institutions, as well as by academics and others interested in monetary and fmancial problems. Since its establishment in 1963 it has developed as a forum for the exchange of information, research results and ideas, valued by academics and practitioners in these fields, including central bank officials and civil servants responsible for formulating and applying monetary and fmancial policies. A major activity of SUERF is to organise and conduct Colloquia on subjects of topical interest to members. The titles, places and dates of previous Colloquia for which volumes of the collected Papers were published are noted on page ii. Volumes were not issued. for Colloquia held at Tarragona, Spain in October 1970 under the title "Monetary Policy and New Developments in Banking" and at Strasbourg, France in January 1972 under the title "Aspects of European Monetary Union".