What do you mean by "mobile"? Multi-applicant inventors in the European Bio-Technology Industry

Many recent papers dealing with the issue of knowledge spillovers have relied on patent data to extract information on so-called mobile inventors that is inventors designated by patent applications filed by different companies. In this paper we follow in this tradition, but with the aim of setting straight a number of methodological issues. By making use of information on the identity and history of those applicants, we then propose a taxonomy of the phenomena behind multi-applicant inventorship, which distinguishes between job mobility, mobility as a result of M&As, a case which we suspect to be dominated by the markets for research and for technologies, and residuals cases. We then argue that different multi-applicant inventors’ categories have to do with different patterns of knowledge diffusion, which include both spillovers and markets for technology.