Characterizing the policy mix and its impact on energy sustainable transformation: The case of China’s energy policy

The study delves into how policy mixes catalyze rapid and sustainable transformation in response to climate change and environmental challenges. Using China’s energy policies as a case study, we quantify indicators of novelty, complementarity, and coherence to evaluate the efficacy of these policy mixes in fostering sustainable transformation. Specifically, we collected and analyzed 16,725 Chinese energy policies as empirical data. Each policy was deconstructed into a vector comprising a series of policy elements (objectives and instruments) and their corresponding intensity levels, capturing the intricate relationships among elements, including migration, emergence, co-occurrence, and supplementary relationships. These element combinations were then mapped into spatial–temporal policy mix characteristics through a bottom-up approach. We compiled a comprehensive panel dataset of energy policy mixes for 284 Chinese prefecture-level cities from 2006 to 2021 to evaluate their impact on enhancing energy efficiency and facilitating transformation. Econometric results indicate that the novelty and complementarity of policy mixes exhibit an inverted U-shaped relationship with energy efficiency. A more coherent deployment strategy of policy mixes significantly promotes energy efficiency. Additionally, these characteristics affect energy efficiency indirectly by altering the trajectory of green technological innovation. Importantly, these effects are unevenly manifested across cities, depending on differences in geographic location, urban scale, governmental efficiency, and resource endowments. Finally, our research revealed inconsistent spatial spillover effects of policy mix characteristics on energy translations, necessitating further investigation to attribute these effects adequately.