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Patents and Cumulative Innovation: Causal Evidence from the Courts


  • Alberto Galasso
  • Mark Schankerman


Cumulative innovation is central to economic growth. Do patent rights facilitate or impede follow-on innovation? We study the causal effect of removing patent rights by court invalidation on subsequent research related to the focal patent, as measured by later citations. We exploit random allocation of judges at the U.S. Court of Appeals for the Federal Circuit to control for endogeneity of patent invalidation. Patent invalidation leads to a 50 percent increase in citations to the focal patent, on average, but the impact is heterogeneous and depends on characteristics of the bargaining environment. Patent rights block downstream innovation in computers, electronics and medical instruments, but not in drugs, chemicals or mechanical technologies. Moreover, the effect is entirely driven by invalidation of patents owned by large patentees that triggers more follow-on innovation by small firms.

Suggested Citation

  • Alberto Galasso & Mark Schankerman, 2013. "Patents and Cumulative Innovation: Causal Evidence from the Courts," CEP Discussion Papers dp1205, Centre for Economic Performance, LSE.
  • Handle: RePEc:cep:cepdps:dp1205

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    References listed on IDEAS

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    Cited by:

    1. Joy Buchanan & Bart Wilson, 2014. "An experiment on protecting intellectual property," Experimental Economics, Springer;Economic Science Association, vol. 17(4), pages 691-716, December.
    2. Chen, Yongmin & Pan, Shiyuan & Zhang, Tianle, 2016. "Patentability, R&D direction, and cumulative innovation," MPRA Paper 73180, University Library of Munich, Germany.
    3. Guido Cozzi & Silvia Galli, 2014. "Sequential R&D and blocking patents in the dynamics of growth," Journal of Economic Growth, Springer, vol. 19(2), pages 183-219, June.
    4. Belleflamme,Paul & Peitz,Martin, 2015. "Industrial Organization," Cambridge Books, Cambridge University Press, number 9781107687899, March.
    5. Boudreau, Kevin J. & Lakhani, Karim R., 2015. "“Open” disclosure of innovations, incentives and follow-on reuse: Theory on processes of cumulative innovation and a field experiment in computational biology," Research Policy, Elsevier, vol. 44(1), pages 4-19.

    More about this item


    patent rights; cumulative innovation; economics of innovation;

    JEL classification:

    • O33 - Economic Development, Innovation, Technological Change, and Growth - - Innovation; Research and Development; Technological Change; Intellectual Property Rights - - - Technological Change: Choices and Consequences; Diffusion Processes
    • O34 - Economic Development, Innovation, Technological Change, and Growth - - Innovation; Research and Development; Technological Change; Intellectual Property Rights - - - Intellectual Property and Intellectual Capital
    • K41 - Law and Economics - - Legal Procedure, the Legal System, and Illegal Behavior - - - Litigation Process

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