The present model is essentially Romer’s (1990) model of endogenous growth with intertemporal knowledge externalities …, augmented with contemporaneous knowledge externalities to give a richer explanation of the growth process. Both types of … complementarities and knowledge externalities across inventive firms immediately creates the possibility of multiple equilibria and …

knowledge externalities if it is located in a geographical area close to R&D intensive users and producers identified by input …&D. Nevertheless, it still remains difficult to predict which local industrial structure may best favor the diffusion of knowledge … externalities and finally innovation. In order to further investigate these issues, this paper studies vertical R&D spillovers in …

knowledge externalities, in order to reveal their role in the organisation of research systems. The aim of this paper is to …