Exploring the Relationship Between R&D and Productivity in French Manufacturing Firms

This paper uses a newly available dataset on the R&D performance of individual French manufacturing firms for the 1980s to replicate and update a series of studies on French R&D and productivity growth at the firm level during the 1970s. The focus of the paper is on the use of a single dataset to evaluate the robustness of the methods commonly used to measure the private returns to R&D. We investigate the consequences of varying specifications and estimations. and in particular that of using different measures of R&D (knowledge) capital and of double counting corrections. Our main findings are the following: first. having a longer history of R&D expenditures helps in predicting the productivity growth of firms, but the choice of depreciation rate for R&D capital makes little difference to the results. Second, the correction for double counting of R&D expenditures in capital and labor is important and converts a measured "excess" rate of returns to a total rate of return to R&D. Third. we show that the direct production function approach to measuring the returns to R&D capital is preferred on several grounds over the rate of returns variation which has been used in the past. Finally