What determines the duration of patent examination in China? An outcome-specific duration analysis of invention patent applications at SIPO

Although China is now the largest patent filing country in the world, research on the duration and outcomes of patent examination remains scarce. In this study, we conduct a replication and extension of Harhoff and Wagner's (2009) work on the determinants of patent examination duration at the European Patent Office (EPO), using a rich dataset covering the population of about 1.1 million invention patent applications to China's State Intellectual Property Office (SIPO) from 1993 to 2006. By considering all three competing examination outcomes (grant, withdrawal, and refusal) simultaneously, our competing risks analysis replicates many of the results in prior research and confirms that a number of the determinants have differential effects on pendencies for different outcomes. Our analysis also reveals several applicant and application characteristics whose effects on pendencies for specific outcomes differ from prior research. Finally, by incorporating a number of new determinants, we report a set of new findings about their effects on the examination duration for the three outcomes at SIPO.