In this volume Professor Harris studies the epidemic of exchange depreciation that since 1931 has directly affected almost the entire world, and attempts to answer the question whether it has done the world more good than harm. Part I is a discussion of important theoretical issues raised by current experiences with exchange depreciation. In Part II Professor Harris makes the most thorough statistical study of the relation of exchange depreciation to prices, trade, and production that has yet been made. Part III is more than a study of exchange depreciation in the United States: it is also a thorough study of the legislation and policies of the Roosevelt Administration, domestic policies being discussed in their relation to exchange depreciation. Finally, the British episode receives attention in Part IV, a separate chapter being devoted to the British Exchange Equalisation Fund and one to the relation of depreciation to British trade, production, and prices.