Relational spillovers and knowledge creation across European regions: are there differences across R&D institutional sectors?

However, the special role of geographical distance with respect to other types of distances has been questioned by a seminal paper of Boschma (2005), claiming that geographical proximity per se is neither a necessary nor a sufficient condition for learning to take place. Cognitive, organizational, social and institutional distances may be equally relevant, although they may be strengthened by geographical proximity.2