Research and development productivity and spillovers: Empirical evidence at the firm level

A variety of methods have been used to investigate the empirical relationship between research and development (R&D) spending and the productivity of firms. The most widely employed frameworks are the production function and the associated productivity framework. In these settings, productivity growth is related to expenditures on R&D, and an attempt is made to estimate statistically the part of productivity growth that can be attributed to R&D activities. This article surveys the expansive body of empirical literature on this subject and finds a large and significant impact of R&D on firm performance on average. However, the estimated returns vary considerably between the different studies due to differences across data samples and econometric models, as well as methodological and conceptual issues. A meta-analysis on the studies surveyed reveals that the estimated rates of return do not significantly differ between countries, whereas the estimated elasticities do. Furthermore, the estimated elasticities are significantly higher in the 1980s and consistently higher in the 1990s compared with the 1970s. Hence, contrary to a widely held belief, we find no convincing evidence of an exhaustion of R&D opportunities in the last two decades.