Over the past decade or so, the regional dimension of innovation policies has propelled a growing level of attention (Bresnahan and Gambardella 2004), and notions such as cluster, learning region, pole de compétitivité, and industrial district have commenced to constitute a relevant geographical unit of analysis for policy interventions in most developed economies. Whereas the importance of local conditions for regional growth has been already articulated by the literature on the so-called marshallian economies, the recent debate has increasingly stressed the critical role for policy of the location of R&D investments, and at the same it has claimed that the geographical concentration of innovative activities is favourable to their efficiency (for a survey see Feldman and Kogler 2010).