Distinguished economists Brus and Laski—who were involved with the Planning Office of the Polish economy in the 1950s and 1960s—here develop a theoretical system of economic management which avoids the failings of both market capitalism and central planning. This book examines Marxists claim to socialism's economic rationality and studies the application of the concept in the "real socialism" of Communist party orthodoxy as well as in the tentative attempts at "market socialism", particularly in Hungary and Yugoslavia. The analysis focuses on general features of the evolution of the socialist economic system, but national experiences are used to point out the advances that have been made and the flaws in the theoretical models that have been developed.