How does competition in firms' product markets influence stock returns? We examine this question using firms domiciled in the UK. We find that firms in less concentrated industries earn higher returns, even after controlling for the well-known determinants of the cross-section of UK stock...

This article examines the effects of market structure on the variety of research projects undertaken and the amount of duplication of research. A characterization of the equilibrium market portfolio of R&D projects and the socially optimal portfolio is provided. It is shown that a merger...

When firms decide to invest in R&D, they have to choose not only the amount of resources to invest, but also which research projects to develop. This paper investigates the market portfolio of research projects. Contrary to most of the literature, which focuses only on the level of investment in...