The writings on the theory of economic growth share almost without exception two characteristics - they deal exclusively with steady growth or equilibrium dynamics, and they try to predict the actual course of long-term development on the basis of greatly oversimplified behaviour assumptions. This book, first published in 1976, studies the many variants of a disequilibrium path, which growth processes pursue under the impact of major growth stimuli - changes in labour supply, in natural resources, and in technology. The study gives direction to public policies, sharply distinguishing between the requirements of market economies and of planned systems.