Marina Ranga participated in the brainstorming that led to this paper and the thorough revision of an earlier version. Catalina Martinez provided us with data to update the database. Both reviewed a previous version of the manuscript. Anabel Fernandez-Mesa, Alberto Marzucchi and Francesco Rentocchini helped with the econometric estimations. Richard Woolley shared insights on the structural composition of research expenditure. Elena M. Tur and Francois Perruchas offered technical assistance. The research was carried out with funding from project GV/2012/018 of the Valencian Regional Government. Previous versions of the paper were presented at the 2013 Eu-SPRI Forum Conference, the 2013 ISSI Conference and the 2013 IPTS Workshop on 'Harnessing the Powers of Patent Data'. The authors acknowledge helpful comments from the audiences, especially Jorge Niosi and Julio Raffo. Joaquin M. Azagra-Caro is grateful to Rene van Bavel and Xabier Goenaga for their institutional support, and to the international consortium that produced the database, especially Henry Etzkowitz, Marina Ranga and members of Incentim and CWTS, led, respectively, by Bart Van Looy and Robert J.W. Tijssen.

[EN] This paper analyses country-specific determinants of knowledge flows with a view to uncover the role of cross-organizational interactions. Using a sample of some 600,000 patents from the EU27 member states in the period 1990-2007, we take backward citations as dependent variable and find that technological sophistication and research size have a positive effect on knowledge flows. While a national bias towards applied research and development has a negative impact, individual public-private cooperation has a moderating effect due to the generation of scientific knowledge by public institutions. The present study contributes to the debate concerning the direction of R&D investments and provides empirical support to policies aimed at the enhancement of public-private cooperation.