Prospects for Improving U.S. Patent Quality via Post-grant Opposition

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.