The microeconomics of an R&D-Based model of endogenous growth

This paper explores the microeconomic structure underlying a class of endogenous growth models in which product differentiation and stochastic quality growth coexist. The general equilibrium model generates a stationary stochastic equilibrium in which a nondegenerate ergodic distribution of firm size depends systematically on parameters of the model. Features of the model necessary for stable endogenous aggregate growth are explored, and predictions of the model are compared with microeconometric evidence on R&D intensity, firm growth, and concentration.