On October 17, 1981, leading economists from throughout the world gathered in Brussels to salute the seventieth birthday of Robert Triffin, the internationally esteemed, Belgain-born economist who is now professor at Louvain Laneuve University in his home country. The form of the salute was the presentation of 18 papers on an issue Triffin has written on throughout his career: the effect of flexible exchange rates on the international monetary system. The classic statement for a system of flexible exchange rates was made by Milton Friedman in 1950, but not until 1973 were these claims put fully to the test. he essays in this volume draw from the past eight years' experience with currencies flloating against one another in exchange markets.