Can intellectual property rights protection reduce air pollution? A quasi-natural experiment from China

China began to implement the National Intellectual Property Rights Demonstration Cities (NIPRDC) policy in 2012 to strengthen intellectual property rights (IPR) system. Few studies have focused on the effects of IPR protection on air pollution. Using a panel data set of 268 Chinese cities from 2003 to 2016, this study is the first to adopt a multi-period difference-in- differences (DID) method to examine the effect and mechanism of the NIPRDC policy on air pollution. The results show that the establishment of NIPRDC can effectively reduce the level of urban air pollution, resulting from the effects of technological innovation and industrial structure. Moreover, the air pollution reduction effect of the NIPRDC policy is found to be more significant in resource-based cities. In addition, panel quantile regression results show that the strength of IPR protection helps to improve air quality in high-polluting areas. These findings provide new evidence for the relationship between IPR protection and air pollution, and also provide policy guidance for developing countries seeking both innovation and environmental protection.