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Incidence and Growth of Patent Thickets - The Impact of Technological Opportunities and Complexity


  • Graevenitz, Georg von
  • Wagner, Stefan
  • Harhoff, Dietmar


We investigate incidence and evolution of patent thickets. Our empirical analysis is based on a theoretical model of patenting in complex and discrete technologies. The model captures how competition for patent portfolios and complementarity of patents affect patenting incentives. We show that lower technological opportunities increase patenting incentives in complex technologies while they decrease incentives in discrete technologies. Also, more competitors increase patenting incentives in complex technologies and reduce them in discrete technologies. To test these predictions a new measure of the density of patent thickets is introduced. European patent citations are used to construct measures of fragmentation and technological opportunity. Our empirical analysis is based on a panel capturing patenting behavior of 2074 firms in 30 technology areas over 15 years. GMM estimation results confirm the predictions of our theoretical model. The results show that patent thickets exist in 9 out of 30 technology areas. We find that decreased technological opportunities are a surprisingly strong driver of patent thicket growth.

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  • Graevenitz, Georg von & Wagner, Stefan & Harhoff, Dietmar, 2011. "Incidence and Growth of Patent Thickets - The Impact of Technological Opportunities and Complexity," Discussion Paper Series of SFB/TR 15 Governance and the Efficiency of Economic Systems 356, Free University of Berlin, Humboldt University of Berlin, University of Bonn, University of Mannheim, University of Munich.
  • Handle: RePEc:trf:wpaper:356

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    References listed on IDEAS

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    More about this item


    Patenting; Patent thickets; Patent portfolio races; Complexity; Technological Opportunities;

    JEL classification:

    • L13 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Oligopoly and Other Imperfect Markets
    • L20 - Industrial Organization - - Firm Objectives, Organization, and Behavior - - - General
    • O34 - Economic Development, Innovation, Technological Change, and Growth - - Innovation; Research and Development; Technological Change; Intellectual Property Rights - - - Intellectual Property and Intellectual Capital

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