The mixed picture of extant research on the relationship between internal and external R&D prompts us to ask such a question: under what conditions is there complementarity or substitutability between different R&D strategies? The goal of this paper is to contribute to the empirical literature...

We examine the impact of internal and external R&D on labor productivity in a 6-year panel of Dutch manufacturing firms. We apply a dynamic linear panel data model that allows for decreasing or increasing returns to scale in internal and external R&D and for economies of scope. We find...