Post-Issue Patent "Quality Control": A Comparative Study of Us Patent Re-Examinations and European Patent Oppositions

45 Pages Posted: 21 Feb 2002 Last revised: 27 Jul 2022

See all articles by Stuart J.H. Graham

Stuart J.H. Graham

Georgia Institute of Technology - Scheller College of Business

Bronwyn H. Hall

University of California at Berkeley; National Bureau of Economic Research (NBER); Institute for Fiscal Studies (IFS); Max Planck Institute for Innovation and Competition

Dietmar Harhoff

Max Planck Institute for Innovation and Competition; Ludwig-Maximilians-Universität München; Centre for Economic Policy Research (CEPR)

David C. Mowery

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

Date Written: February 2002

Abstract

We report the results of the first comparative study of the determinants and effects of patent oppositions in Europe and of re-examinations on corresponding patents issued in the United States. The analysis is based on a dataset consisting of matched EPO and US patents. Our analysis focuses on two broad technology categories - biotechnology and pharmaceuticals, and semiconductors and computer software. Within these fields, we collect data on all EPO patents for which oppositions were filed at the EPO. We also construct a random sample of EPO patents with no opposition in these technologies. We match these EPO patents with the 'equivalent' US patents covering the same invention in the United States. Using the matched sample of USPTO and EPO patents, we compare the determinants of opposition and of re-examination. Our results indicate that valuable patents are more likely to be challenged in both jurisdictions. But the rate of opposition at the EPO is more than thirty times higher than the rate of re-examination at the USPTO. Moreover, opposition leads to a revocation of the patent in about 41 percent of the cases, and to a restriction of the patent right in another 30 percent of the cases. Re-examination results in a cancellation of the patent right in only 12.2 percent of all cases. We also find that re-examination is frequently initiated by the patentholders themselves.

Suggested Citation

Graham, Stuart J.H. and Hall, Bronwyn H. and Harhoff, Dietmar and Mowery, David C., Post-Issue Patent "Quality Control": A Comparative Study of Us Patent Re-Examinations and European Patent Oppositions (February 2002). NBER Working Paper No. w8807, Available at SSRN: https://ssrn.com/abstract=301428

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

Bronwyn H. Hall (Contact Author)

University of California at Berkeley ( email )

549 Evans Hall #3880
Berkeley, CA 94720-3880
United States

HOME PAGE: http://emlab.berkeley.edu/users/bhhall/index.html

National Bureau of Economic Research (NBER)

1050 Massachusetts Avenue
Cambridge, MA 02138
United States

Institute for Fiscal Studies (IFS)

7 Ridgmount Street
London, WC1E 7AE
United Kingdom

Max Planck Institute for Innovation and Competition

Marstallplatz 1
Munich, Bayern 80539
Germany

Dietmar Harhoff

Max Planck Institute for Innovation and Competition ( email )

Marstallplatz 1
Munich, Bayern 80539
Germany
+49 89 24246 550 (Phone)
+49 89 24246 599 (Fax)

HOME PAGE: http://www.ip.mpg.de

Ludwig-Maximilians-Universität München ( email )

Munich, 80539
Germany

Centre for Economic Policy Research (CEPR)

London
United Kingdom

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

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