In a modern economy, production and competition require internal interaction of individuals in firms. The book provides a systematic treatment of the macroeconomic consequenses of this fact. For this purpose the concept of a two-stage monopolistic competition equilibrium is introduced into macroeconomic theory. Firms choose the capacity to organize internal interaction at stage 1 and compete at stage 2. The concept allows a rigorous analysis of the provision of work places and the economic determinants of the employable work force. The book explains why in the equilibrium of a market economy,...