Patent Count Data as an Indicator of Innovation Output


  • Are available to the public,
  • Contain considerable detail, and
  • Are available over time, enabling time series analysis.


  • Some important technologies are not patentable, such as software that is protected by copyright.
  • Not all inventions are patented. Firms protect the returns to their investment in other ways such as through secrecy, lead-time advantages, and marketing.
  • Firms patent for different reasons, not all of them related directly to commercial exploitation, for example, to protect an invention from imitation, to block competitors from patenting or pursuing a line of research, or to evaluate the productivity of their R&D activities. This adds considerable uncertainty to the interpretation of patent count data.
  • Patents represent only the practical application of ideas, not more general advances in knowledge.
  • Patents represent inventions, not activities and investments to commercialize new technology.
  • Patents have widely varying commercial value and therefore significance with respect to innovation.

One suggestion for improving the usefulness of patent count data was to ask companies to list on the RD-1 survey form the names of the entities under which they hold patents. With this information, one could match R&D expenditures to the patent data and create a series for patents by industry that corresponds to existing data series on R&D by industry. Some participants also noted current efforts to use the information gathered by innovation surveys (e.g., on the use of patents relative to other means of appropriating returns to innovation) and to weight patent counts by industry.

The front page of U.S. patents contains citations of previous patents and other critical scientific literature purportedly representing the intellectual lineage or prior art of the patented invention and distinguishing it from previous inventions. In principle, patent citation data contain a wealth of micro-information on

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