Skip to main content
  • Bronwyn H. Hall, Christian Helmers, and Georg von Graevenitz, "Technology Entry in the Presence of Patent Thickets," NBER Working Paper 21455 (2015), https://doi.org/10.3386/w21455.

Published Versions

Bronwyn H Hall & Georg von Graevenitz & Christian Helmers, 2021. "Technology Entry in the Presence of Patent Thickets," Oxford Economic Papers, Oxford University Press, vol. 73(2), pages 953-953. citation courtesy of

Bronwyn H Hall & Georg von Graevenitz & Christian Helmers, 2021. "Technology entry in the presence of patent thickets [Our divided patent system?]," Oxford Economic Papers, Oxford University Press, vol. 73(2), pages 903-926. citation courtesy of

More from the NBER

In addition to working papers, the NBER disseminates affiliates’ latest findings through a range of free periodicals—the NBER Reporter, the NBER Digest, the Bulletin on Health, the Bulletin on the Economics of Alzheimer's, and the Bulletin on Entrepreneurship—as well as research spotlights, lectures, and panel videos.

2026, 18th Annual Feldstein Lecture, Mark Duggan, "Social Security Reform in an Era of Fiscal Deficits" Primary tabs
  • Feldstein Lecture
Mark Duggan, who is currently the Wayne and Jodi Cooperman Professor of Economics at Stanford University and will soon...
SI 2026 Methods Lecture
  • Methods Lectures
Research Associate Melissa Dell of Harvard University and Ashesh Rambachan of MIT delivered the 2026 Methods...