This paper presents a simple R&D-driven endogenous growth model to shed light on some puzzling economic trends. The model can account for why patent statistics have been roughly constant even though R&D employment has risen sharply over the last 30 years. The model also illuminates why steadily increasing R&D effort has not led to any upward trend in economic growth rates, as is predicted by earlier R&D-driven endogenous growth models with the "scale effect" property.

This paper develops a dynamic general equilibrium model of economic growth. The model has a steady-state equilibrium in which some firms devote resources to discovering qualitatively improved products and other firms devote resources to copying these products. Rates of both innovation and imitation are endogenously determined on the basis of the outcomes of $R & D$ races between firms. Innovation subsidies are shown to unambiguously promote economic growth. Welfare is enhanced, however, only if the steady-state intensity of innovative effort exceeds a critical level.

This paper presents a simple R&D-driven endogenous growth model to shed light on some puzzling economic trends. The model can account for why patent statistics have been roughly constant even though R&D employment has risen sharply over the last 30 years. The model also illuminates why steadily increasing R&D effort has not lead to any upward trend in economic growth rates, as is predicted by earlier R&D-driven endogenous growth models with the “scale effect ” property.

This paper develops a dynamic general equilibrium model of economic growth. The model has a steady-state equilibrium in which some firms devote resources to discovering qualitatively improved products and other firms devote resources to copying these products. Rates of both innovation and imitation are endogenously determined on the basis of the outcomes of $R & D$ races between firms. Innovation subsidies are shown to unambiguously promote economic growth. Welfare is enhanced, however, only if the steady-state intensity of innovative effort exceeds a critical level.

This paper presents a dynamic general equilibrium model of North-South trade in which research and development races between firms determine the rate of product innovation in the North. Tariffs designed to protect dying industries in the North from Southern competition reduce the steady-state number of dominant firms in the North, reduce the rate of product innovation, and increase the relative wage of Northern workers.

This paper presents a dynamic general equilibrium model of North-South trade in which research and development races between firms determine the rate of product innovation in the North. Tariffs designed to protect dying industries in the North from Southern competition reduce the steady-state number of dominant firms in the North, reduce the rate of product innovation, and increase the relative wage of Northern workers.