We reexamine several bodies of data on the growth of output, labor, and capital, within the context of a model that admits the possibility of an externality to the capital input. The model is an augmented version of Paul Romer's (1987) reformulation of the Solow model. Unlike Romer, however, we...

We study how innovation and technology diffusion interact to endogenously determine the productivity distribution and generate aggregate growth. We model firms that choose to innovate, adopt technology, or produce with their existing technology. Costly adoption creates a spread between the best...