Pioneering Inventors or Thicket-Builders: Which Firms Use Continuations in Patenting?

Management Science, Vol. 55, No. 7, July 2009

38 Pages Posted: 12 Apr 2011 Last revised: 29 Oct 2015

Deepak Hegde

New York University (NYU) - Leonard N. Stern School of Business

David C. Mowery

University of California, Berkeley - Haas School of Business; National Bureau of Economic Research (NBER)

Stuart J.H. Graham

Georgia Institute of Technology - Scheller College of Business

Date Written: February 8, 2009

Abstract

Why do firms use continuations in the prosecution of their patents? Motivated by the widespread use of continuations by U.S. firms and the prominence of this procedure in U.S. patent policy debates, we investigate the influence of corporate and patent characteristics on the use of continuations. We employ novel data on applicants and their filings of three types of continuations - the continuation application (CAP), the continuations in part (CIP), and divisions - during 1981-2000 to distinguish among the motives for continuing patents. We find that CIPs are disproportionately filed by research and development-intensive firms that patent heavily, and that these continuations are more common in chemical and biological technologies. Patents issuing from CIPs cover relatively important inventions and their use appears consistent with a strategy of protecting "pioneering inventions." In contrast, CAPs and divisions are associated with less important patents assigned to capital-intensive firms, particularly in computer and semiconductor fields, and appear to be used in defensive patenting strategies. We analyze the effects of the 1995 change in patent term, and find that the act reduced continuations overall and shifted the output of continuations toward less important patents.

Suggested Citation

Hegde, Deepak and Mowery, David C. and Graham, Stuart J.H., Pioneering Inventors or Thicket-Builders: Which Firms Use Continuations in Patenting? (February 8, 2009). Management Science, Vol. 55, No. 7, July 2009. Available at SSRN: https://ssrn.com/abstract=1807073

Deepak Hegde (Contact Author)

New York University (NYU) - Leonard N. Stern School of Business ( email )

44 West 4th Street
New York, NY NY 10012
United States

David C. Mowery

University of California, Berkeley - Haas School of Business ( email )

545 Student Services Building, #1900
2220 Piedmont Avenue
Berkeley, CA 94720
United States

National Bureau of Economic Research (NBER)

1050 Massachusetts Avenue
Cambridge, MA 02138
United States

Stuart J.H. Graham

Georgia Institute of Technology - Scheller College of Business ( email )

800 West Peachtree St. NW
Atlanta, GA 30308
United States
404-385-0953 (Phone)
404-894-6030 (Fax)

HOME PAGE: http://https://www.scheller.gatech.edu/graham

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