Skip to main content
Article thumbnail
Location of Repository

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

By Georg von Graevenitz, Stefan Wagner and Dietmar Harhoff


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.

Topics: Discussion Paper Series of SFB/TR 15 Governance and the Efficiency of Economic Systems, C2 - Intellektuelles Eigentum, Aneignung von Innovationserträgen und Innovationswettbewerb, ddc:330
Year: 2011
DOI identifier: 10.1111/joie.12032
OAI identifier:
Provided by: Open Access LMU

Suggested articles


  1. (2008). Shifting Trends
  2. (2005). Supermodularity and Complementarity in Economics: An Elementary Survey,”
  3. (2003). Panel Data Econometrics, Advanced Texts in Econometrics,
  4. (1995). Another Look at the Instrumental-Variable Estimation of Error-Components Models,”
  5. (2004). Patent Thickets: Strategic Patenting of
  6. (2008). Patent Failure,
  7. (1998). Initial Conditions and Moment Restrictions in Dynamic Panel Data Models,”
  8. (2002). Dynamic Panel Data Models: A Guide to
  9. (2006). Traces of Prior Art: An Analysis of Non-patent References Found in Patent Documents,”
  10. (2008). Fragmented Property Rights and Incentives for
  11. (2000). Protecting their Intellectual Assets: Appropriability Conditions and Why U.S. Manufacturing Firms Patent (or Not),” Working
  12. (2003). To Promote Innovation - The Proper Balance of Competition and Patent Law and Policy,”
  13. SCOTCHMER (2002): “Intellectual Property: When Is It the Best Incentive System?”
  14. (1997). Managing Intellectual Capital: Licensing and Cross-Licensing in
  15. (2005). Exploring the Patent Explosion,”
  16. A Note on the Bias in Herfindahl-type Measures Based on
  17. (2001). The Patent Paradox Revisited: An Empirical Study of Patenting in the U.S. Semiconductor Industry,
  18. (2006). European Patent Citations - How to count and how to interpret them,” .
  19. (1962). Coherent (visible) Light Emission from Ga (AsP)
  20. (2004). Innovation and Its Discontents: How Our Broken Patent System is Endangering Innovation and Progress, and What to Do About It.,
  21. (1998). Stronger Protection or Technological Revolution: What is Behind the Recent Surge
  22. (1999). What is behind the Recent Surge in
  23. (2004). Protecting Intellectual Property Rights: Are Small Firms Handicapped?”
  24. (1980). Market Structure and Innovation:
  25. (2000). Patent Citations in a Novel Field of Technology - What can they tell about Interactions Between Emerging
  26. (1990). Rationalizability, Learning and Equilibrium
  27. (1997). The Increasing Linkage Between U.S.
  28. (1994). Using Patent Data as Science and Technological Indicators,
  29. (1989). The Timing of Innovation: Research,
  30. (2004). The modern firm,
  31. (2006). How to Do xtabond2: An Introduction to ”Difference” and ”System”
  32. (2005). Innovation and Incentives,
  33. (2001). Navigating the Patent Thicket: Cross Licenses, Patent Pools, and Standard-Setting,”
  34. (2010). Jostling for Advantage or Not: Choosing Between Patent Portfolio Races and Ex Ante Licensing,”
  35. (2007). Combining Patent Law Expertise with R&D for Patenting Performance,” Organization Science.
  36. (1999). Oligopoly Pricing, Old Ideas and New Tools,
  37. (2005). Complementarities and Games: New Developments,”
  38. (2009). How to Measure Patent Thickets - A Novel Approach,” Discussion Paper 2009-9,
  39. (2007). TheStrategicUseofPatentsanditsImplicationsforEnterprise and Competition Policies, Report for the European Commission.
  40. (2005). A Finite Sample Correction for the Variance of Linear Efficient Two-step
  41. (2004). Don’t Fence Me In: Fragmented Markets for Technology and the Patent Acquisition

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.