All results have been reviewed to ensure that no confidential data are disclosed. The authors would like to thank Carol Corrado, Jonathan Haskel, Daniel Sichel, and Javier Miranda-the organizers of the 2017 CRIW Conference on Measuring and Accounting for Innovation in the 21st Century, conference participants, and especially the discussant, Mark Roberts, for helpful comments and suggestions. Veronika Penciakova provided expert research assistance. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.