This book collects together the basic documents of an approach to the theory of the balance of payments and balance of payments policy developed in the 1970s. The approach marked a return to the historical traditions of international monetary theory after some thirty years of departure from them a departure occasioned by the international collapse of the 1930s, the Keynesian Revolution and a long period of war and post-war reconstruction in which the international monetary system was fragmented by exchange controls, currency inconvertibility and controls over international trade and capital movements.