R&D and productivity: Internal vs. external R&D - evidence from west german manufacturing industries

The paper explores the productivity effects of investment in external (contract) vs. internal (in-house) R&D in a sample of West-German Manufacturing Industries. The results provide strong evidence of a positive relationship between productivity and the share of external R&D in total R&D. This result is robust to alternative econometric specifications. Thus, findings suggest that the decision between internal and external R&D does matter. Moreover, results imply a nonlinear relationship between productivity and the share of external R&D for higher-technology industries, hinting at decreasing productivity effects of an increasing share of external in total R&D.