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Patents are a very useful tool for supporting innovations by setting incentives for companies to invest in research and developments. However, only those innovations should be protected by a patent that are truly inventive. Otherwise, patents might actually end up stifling innovations rather than supporting them. This happens in the case of patent thickets where there are overlapping patents that block each other. DIETMAR HARHOFF explains that this situation should be avoided by the mechanism of opposition: After the patent is granted by the patent examiner, third parties have the opportunity to oppose the examiner’s decision. As described in this video, the researchers used graph theory to analyze patent thickets involving three companies to uncover in which situations this instrument fails. Their findings indicate that, if a patent holder is embedded in such a thicket, they are less likely to challenge a patent application to avoid an escalation between the parties that might end up in court. Furthermore, if there is a large number of companies that could oppose a certain patent, the incentive for any of these companies to oppose is reduced as only one of them has to shoulder the costs of the process while all of them benefit.


Dietmar Harhoff is Director at the Max Planck Institute for Innovation and Competition in Munich where he heads the department of Innovation and Entrepreneurship Research. Furthermore, he is an Honorary Professor for Entrepreneurship and Innovation at the Ludwig Maximilian University Munich.
Harhoff’s research focuses on innovation research, entrepreneurship, intellectual property and industrial economics and has been published in a large number of renowned journals. He also serves as a scientific advisor for public and private organizations and chairs the Commission of Experts for Research and Innovation that has been appointed by the German Federal Government. Furthermore, he is an elected member of the German Academy of Science and Engineering (acatech), the German Academy of Sciences Leopoldina and the Bavarian Academy of Sciences (BAdW).


Max Planck Institute for Innovation and Competition

The Max Planck Institute for Innovation and Competition is committed to fundamental legal and economic research on processes of innovation and competition and their regulation. The research focuses on the incentives, determinants and implications of innovation. With an outstanding international team of scholars and excellent scientific and administrative infrastructure including our renowned library, the Institute hosts academics from all over the world and actively promotes young researchers. The Institute informs and guides legal and economic discourse on an impartial basis. As an independent research institution, it provides evidence-based research results to academia, policymakers, the private sector as well as the general public.

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Original publication

Conflict Resolution, Public Goods and Patent Thickets

Harhoff Dietmar, Wagner Stefan and Graevenitz Georg von
Management Science
Published in 2016

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