How does the nested structure affect policy innovation?: Empirical research on China's low carbon pilot cities

The pilot project of low-carbon cities is an important effort to align China's national goals for climate change governance with local governments' low-carbon behavior. The purpose of such pilot project is to promote low-carbon development and encourage policy innovation, but the role of nested structure has not been fully appreciated. Based on the survey data of low-carbon pilot cities, this paper finds that nested structure has a positive impact on policy innovation and discusses the impact on policy innovation from three dimensions: the nested pilot, the nested policy and the nested department. Heckman selection Model and Possion Model are used to make an empirical analysis of the factors influencing policy innovation and used a case study to explore the mechanism. The results show that the nested structure has a positive effect on policy innovation in pilot projects of low-carbon cities with weak incentives and weak constraints. Specifically, the participation of local governments in low-carbon related pilot projects, the number of low-carbon policies introduced by local governments, and the participation of local government departments in the process of low-carbon governance have a positive impact on policy innovation. Nested structure promotes policy innovation mainly through coordination mechanism and funding mechanism.