Post-grant patent review in China: an empirical analysis

With a series of policies to stimulate innovation and patent activities, China has become a world leader in both patent applications and patent litigation. These major developments, together with the escalated US-China trade tensions, have made China an integral but controversial venue for international patent protection. The Chinese patent system, especially its detailed practice and cases, is in need of a comprehensive empirical study. This article analyzed 8766 Chinese patent invalidity cases decided between 2014 and 2016, which, together with my prior work on patent infringement lawsuits, offers a comprehensive picture on how the bifurcated patent system in China works. First, it found that only a small number, about 2.0 percent, of Chinese patents are ever subject to infringement or invalidity disputes, shedding light on the patent office's rational ignorance of a patent's validity at first place. Second, it found that the invalidity rate for invention patents in China (54.6%) was lower than in many other countries, such as the US (83.9%) and Germany (73%), indicating that the Chinese patent system is more pro-patentee than once believed. Third, it raised the question of Chinese patents’ quality based on various characteristics of these cases, including patent types and petitioners’ entity status.