The role of diminishing returns in neo-Schumpeterian growth theory

Summary. This paper generalizes Segerstrom 5], a dynamic general equilibrium model of endogenous growth through quality improvements in which innovation and imitation are modeled as the outcomes of research and development (R&D) races. Specific factors introduced into the technologies of both R&D activities achieve diminishing returns to scale in R&D. The comparative-static results of subsidies to R&D activities depend on the degree of diminishing returns to scale in R&D. When there is (is not) a sufficient degree of diminishing returns to R&D, a subsidy to innovative activity increases (decreases) innovative activity. Received: July 8, 1994; revised version: June 9, 1997