This book gives a comprehensive account of traditional and more recent developments in macroeconomic theory. It is primarily written for students at the intermediate level. The book differs from the customary expositions in that the authors do not discuss topic by topic, but doctrine by doctrine. Thus, the main approaches, such as Classical theory, Keynesian theory, theory of portfolio selection, monetarism, rational expectations theory, and Neokeynesian "disequilibrium" theory, are presented in historical order. Each of these approaches is substantiated and criticized in a self-contained chapter, and the authors have taken great efforts to bring out the relations and differences between them. A Mathematical Appendix contains reviews of those mathematical facts which are especially important to macroeconomic models and makes the text easy to read.