NBER Working Papers by Stuart Graham

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Working Papers

November 2007Competing on Standards? Entrepreneurship, Intellectual Property and the Platform Paradox
with Timothy S. Simcoe, Maryann Feldman: w13632
This paper studies the intellectual property strategy of firms that participate in the formal standards process. Specifically, we examine litigation rates in a sample of patents disclosed to thirteen voluntary Standard Setting Organizations (SSOs). We find that SSO patents have a relatively high litigation rate, and that SSO patents assigned to small firms are litigated more often than those of large publicly-traded firms. We also estimate a series of difference-in-differences models and find that small-firm litigation rates increase following a patent's disclosure to an SSO while those of large firms remain unchanged or decline. We interpret this result as evidence of a "platform paradox" -- while small entrepreneurial firms rely on open standards to lower the fixed cost of innovation, th...
June 2007Pioneers, Submariners, or Thicket-builders: Which Firms Use Continuations in Patenting?
with Deepak Hegde, David C. Mowery: w13153
The continuations procedure within the U.S. patent system has been criticized for enabling firms to manipulate the patent review process for strategic purposes. Changes during the 1990s in patent procedures affected the incentives of applicants to exploit the continuations process, and additional reforms in continuations currently are being considered. Nonetheless, little is known about applicants' use of the three major types of continuations -- the Continuation Application (CAP), the Continuations-In-Part (CIP), and Divisions -- to alter the term and scope of patents. This paper analyzes patents issued from the three types of continuations to U.S. firms during 1981 - 2004 (with priority years 1981 - 2000), and links their frequency to the characteristics of patents, assignees and indu...
May 2003Prospects for Improving U.S. Patent Quality via Post-grant Opposition
with Bronwyn H. Hall, Dietmar Harhoff: w9731
The recent surge in U.S. patenting and expansion of patentable subject matter has increased patent office backlogs and raised concerns that in some cases patents of insufficient quality or with inadequate search of prior art are being issued. At the same time patent litigation and its costs are rising. This paper explores the potential of a post-grant review process modeled on the European opposition system to improve patent quality, reveal overlooked prior art, and reduce subsequent litigation. We argue that the welfare gains to such a system may be substantial.
February 2002Post-Issue Patent "Quality Control": A Comparative Study of US Patent Re-examinations and European Patent Oppositions
with Bronwyn H. Hall, Dietmar Harhoff, David C. Mowery: w8807
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...

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