Recent empirical studies of firm-level performance have tested complementarity in the case of multiple practices. These papers have drawn conclusions using potentially biased estimates of pair-wise interaction effects. We develop a consistent and simple testing framework and test it against...

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...