When interaction matters: the contingent effects of spatial knowledge spillovers and internal R&I on firm productivity

This work studies the linkages between spatially bound knowledge spillovers, internal research, and innovation (R&I) activities and firm productivity. Spillovers are modeled to emanate from intra- and extra-sectoral R&I activities in the firms’ regional business environments. We specifically test for non-linearities in the complex relationship between these internal and external knowledge sources and quantify their joint marginal effect on firm...