Paper prepared for the Conference on Agglomeration Economies and Regional Growth

In this paper we address the manifold nature of knowledge through the analysis of four distinct but complementary phenomena (Internet hyperlinks, European research networks, EPO co-patent applications, Erasmus students mobility) which characterize knowledge as an intrinsic relational structure (directly) connecting people, institutions and (indirectly) regions across five European countries. We firstly study the structure (in terms of density, clustering and centralisation) of these networks flows through network analysis techniques and we test the influence of geographical distance as opposed to sectoral (based on the industrial distribution of the innovative activity) and functional (based on the value of the RSII European technological leadership index) distances in shaping the strength of knowledge relations though a gravitational model. The empirical analysis shows the existence of a polarized centre-periphery hierarchy of European regions which is reflected in the structure of knowledge flows By using a “gravitational ” model we demonstrated that, far from the claim of the “death of distance”, geographic distance is still relevant for determining the structure of inter-regiona