Death squad or quality improvement? The impact of introducing post-grant review on U.S. patent legal quality
研究了美国发明法案引入授权后审查如何促使专利申请人缩小专利范围、审查员加强审查，从而提升专利法律质量，但在专利丛林的复杂领域效果不明显。
We investigate how the introduction of post-grant reviews at the U.S. Patent and Trademark Office through the America Invents Act (AIA) has influenced the behavior of patent applicants and examiners. This reform may incentivize applicants to narrow the scope of their patents, thereby reducing the risk of post-grant reviews and enhancing patent legal quality. To test this hypothesis, we employ a standard Difference-in-Differences (DID) analysis and find that applicants are more likely to narrow the scope of their patents. This change has resulted in fewer challenges to U.S. patents, yielding estimated annual savings of 62 to 148 million. When applicants do not preemptively narrow the scope during filing, we observe tougher scrutiny during the examination process, as examiners effectively compensate for the applicant’s lack of action. However, this “disciplinary effect” of narrowing patent scope is absent in complex fields characterized by patent thickets, where the reform does not lead to significant improvements in U.S. patent legal quality. • Post-grant reviews may lead to patents of a narrower scope, improving patent quality. • We study how applicants and examiners react to the introduction of post-grant reviews in the U.S. • Identification is based on twin applications for the same invention at USPTO and CIPO. • Post-grant reviews induce a disciplinary effect on applicants and examiners to narrow patent scope. • The patent quality improvement does not occur in fields with patent thickets.