R&D and market structure: The impact of measurement and aggregation problems

Estimates on the relationship between concentration and R&D effort are shown to be sensitive to problems of aggregation and of adequate measurement of R&D in small firms. While estimates from the official R&D survey of the Netherlands show a highly significant linear relationship between concentration and R&D, comparable estimates from our R&D data base prove it to be insignificant. However, at a finer level of disaggregation and when our sample is split into sectors with low and high technological opportunities, we discover evidence of a quadratic relationship in the latter and evidence of a weak linear relationship in the former.