In a non-market-clearing approach to business cycle theory, this book builds an advanced model of economic activity, inflation and income distribution in a Keynesian spirit. After a qualitative analysis of the basic feedback mechanisms, the authors calibrate the model to the stylized facts of the business cycle in the U.S. economy. This calibrated model is used to carry out various macroeconomic simulation studies as well as a detailed study of the macroeconomic impact of various monetary policy rules. It will appeal both to theorists and to applied and policy economists.