Movement of inventors and the effect of knowledge spillovers on spread of innovation: Evidence from patent analysis in high-tech industries

Over the past decades, many researchers have attributed growth and evolution of new technologies partly to knowledge spillovers among inventors and corporations. Patents and patent citations are considered as indicators of such knowledge transfer as a citing patent acknowledges the prior knowledge embedded in the cited patent. In this paper, the authors examine the effect of knowledge spillovers on patenting behavior of the inventors. In particular, would an inventor moving from one company to another acquire new knowledge and can this knowledge be transferred implicitly through his/her future innovations? The authors attempt to answer this question by studying the patenting behavior of a sample of inventors in high-tech industries from 1990 to 2005. The study shows a positive relationship between inventors' movements to their ability to create patents in patent classes outside the classes they previously patented in. The paper reports the results of this study for inventors in telecommunications, information technology and biopharmaceutical industries throughout the US.