Source: Philipp Böing and Elisabeth Müller, “Measuring China’s patent quality: Development and validation of ISR indices,” April 2019, ZEW Discussion Papers, No. 19-017, Leibniz Centre for European Economic Research.
Commentary: China’s patent output has grown dramatically in recent years, both in terms of the volume of patents submitted for international protection under the Patent Cooperation Treaty (PCT) and in terms of the number of citations those patents receive, a standard measure of a patent’s importance. New research breaking down the sources of those citations raises significant doubts about whether the growth in Chinese patent citations is as meaningful as it appears. From 2001 to 2009, Chinese PCT applications received an average of 90 percent as many citations as other nations’ applications, increasing dramatically from 36.3 percent to 151.8 percent over this period. Yet Chinese applications received only 32.1 percent as many citations from foreign nations as other applications during this period (declining from 44.9 percent in 2001 to 30.4 percent in 2009). Most starkly, 71.6 percent of the growth in Chinese citations come from authors citing their own patents, which Chinese authors did over 3 times more than average in 2009.
