Product diffusion and pricing with market frictions

We study pricing and product diffusion in a dynamic general equilibrium framework with product market frictions. Ongoing R&D activity leads, with an endogenously determined probability, to continual improvements in product quality. We characterize the steady-state equilibrium with endogenous product diffusion in which a number of different goods co-exist on the quality ladder. We show that the severity of the economy's market frictions is a crucial determinant of the pricing structure, the product diffusion pattern, the level of R&D investment, the rate of endogenous growth, the length of Schumpeterian product cycles and the possibility of multiple growth paths. Eliminating market frictions leads to a degenerate product ladder of precisely one step, containing only the most recent product, as in the monopolistic competition literature.