تاثیر سرریزهای R & D درتولید بهره وری کل عوامل در انگلستان : یک رویکرد پنل پویا

One of the benefits claimed for investment in Research and Development (R&D) is that there is a spillover effect. Industries benefit from both their own R&D efforts as well as the efforts of other national and overseas industries. The present research presents new evidence on the long-term impact of R&D investment upon UK industry's productivity performance and on the nature of these “R&D spillovers”. The results suggest that R&D efforts from the industry itself and from other national industries have a positive impact on the industry's productivity but, interestingly, there is no gain from foreign R&D investment.

Advances in knowledge through technical change are regarded as a key determinant of productivity growth in the long run. Research and development (R&D) investment directly contributes to knowledge accumulation, hence R&D activities are a potentially important source of productivity gains and ultimately a source of economic growth.1 A large number of empirical studies have concluded that both domestic and foreign R&D are major drivers of economic growth.2 Having recognised the contribution of R&D spillovers to productivity growth, it is only recently that the empirical measure of the magnitude and the direction of such effects has become a major point in the research agenda on the economics of innovation.

The purpose of this paper was to examine the influence of different methodological and measurement issues on studying the relationship between productive knowledge and TFP. Our emphasis was placed upon the long-term relationship between innovative efforts and productivity and the nature of the R&D spillovers accruing to UK manufacturing industries over the period 1970–1997. In contrast to other studies in this tradition, this study focused on gross output as a measure of real output and allowed for imperfect competition and temporary disequilibria. In particular, using the PMG estimator and allowing for heterogeneous dynamic adjustments towards a common long-run equilibrium, we showed that there is a positive and significant link between an industry's R&D activities and productivity in the long term. Specifically, the estimated long-run output elasticity with respect to own R&D is 0.331. In addition, robust evidence was found of positive and significant domestic cross-industry R&D spillovers. These results support the view that private R&D provides public benefits. Furthermore, the private marginal product of investment in R&D may be considerably lower than the social marginal product at the industry level. The presence of spillover effects means that the market will tend to under-invest in innovation from the social point of view. This provides a rationale for Government intervention to sharpen incentives for firms to increase the level of privately funded R&D.