New Ideas in Invention
A key decision in research is whether to try out new ideas or build on more established ideas. In this paper, we evaluate which type of work is more likely to spur further invention. When recent advances create superior opportunities for invention, their adoption as research inputs in the invention process promotes technological progress. The gains from pursuing such innovative research paths may, however, be very limited as new ideas are often initially raw and poorly understood. We determine idea inputs in invention based on the text of nearly every US patent granted during 1836–2010. We find that inventions that build on new ideas early are more likely to spur subsequent invention than inventions that rely on ideas of older vintage. Our results are important because they suggest a benefit from encouraging and supporting innovative research that tries out new ideas — avoiding stagnation in technological advance.
A previous version of this paper was circulated under the title "Words in Patents: Research Inputs and the Value of Innovativeness in Invention.'' We thank Darius Lakdawalla, Dana Goldman, Alan Garber, Richard Freeman, John Ham, Josh Graff Zivin, David Blau, Joel Blit, Subhra Saha, Tom Philipson, Neeraj Sood, Pierre Azoulay, Grant Miller, Jeremy Goldhaber-Fiebert, and Gerald Marschke for their comments on early drafts of this paper and for their encouragement. We also thank seminar participants at the Harvard Business School, Stanford School of Medicine, University of Guelph, and especially Bruce Weinberg's working group on innovation and science at the NBER for excellent feedback. Despite all this help, the authors are responsible for all errors in the paper. We acknowledge financial support from the National Institute on Aging grant P01-AG039347. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.