European integration and knowledge flows across European regions.

There is a large literature on geographically localized knowledge flows. However, technological advances in the field of transportations and communications and the greater integration among countries suggest that knowledge flows are becoming less localized. Using data on patent citations and collaboration among inventors for the period 1981-2000, this article analyses the evolution over time of the impact of geographical distance and national border on the diffusion of knowledge between European regions. We also investigate whether the European integration process has contributed to changing the geographical diffusion of knowledge across European regions. Our results show that geographical distance and national border are important barriers to knowledge flows and that their effects are greater for technological collaboration than in the case of patent citations. Although knowledge flows between European regions remain geographically localized, we show that the propensity for inventors to collaborate within the same country has decreased, while the inventor propensity to cite national originating patent has increased. The effect of geographical distance is decreased only for inventor collaborations. We show also that the EU enlargement processes have favoured international knowledge flows among EU members, although with significant differences between the two measures of knowledge flows.