Gibrat's Law of proportionate effect, as applied to firms, states that the growth rate of a firm is independent of its size. Empirical work on firm dynamics finds crucial deviations from Gibrat's Law such as smaller firms growing faster than larger firms (Evans, 1987, and Hall, 1987), a negative...

In a set of influential papers, Charles Jones (1995a, 1995b, 1999) argued that R&D based endogenous growth models are inconsistent with the data. He showed, in a very striking manner, that the scale effects prediction of early endogenous growth models (e.g. Romer, 1986 and 1990, Grossman and...

When firms engaged in R&D are observably heterogenous (in size) and policymakers are able to condition policy on the observed heterogeneity, what is the optimal policy? This paper starts with a static two-stage duopoly model of R&D competition with uncertainty and finds it welfare enhancing to...