Energy efficiency is the key to green development, and the government plays a vital role in energy efficiency. This paper clarifies the mechanism by which the Yangtze River Delta Economic Coordination Committee affects the energy efficiency of urban agglomeration by promoting market integration. Based on panel data of China's prefecture-level cities from 2004 to 2017, we take the Yangtze River Delta Economic Coordination Committee as a quasi-natural experiment of government cooperation and use the difference-in-difference method to test whether this organization has enhanced the energy efficiency of urban agglomeration. The results show that the Yangtze River Delta Economic Coordination Committee can significantly improve energy efficiency in urban agglomerations. The mechanism analysis shows that it reduces the energy consumption per unit of gross domestic product by enhancing the marketization level, perfecting the relationship between the government and the market, and improving the factor market development. The heterogeneity analysis shows that cities with lower city size, lower level of innovation, and cleaner industrial structures gain more benefits in energy efficiency from government cooperation in urban agglomeration. This paper provides empirical evidence for cities to realize integrated energy conservation through government cooperation and market integration.

This paper evaluates the real effects of pollution charges reform on ${\mathrm{SO}}_2$ emissions at the city level. Using the establishment of Comprehensive Work Plan for Energy Conservation and Emission Reduction (The Plan) in China as a quasi-natural experiment, our difference-in-differences estimation shows that: (1) increasing pollution charges has a significant and positive effect on controlling industrial waste ${\mathrm{SO}}_2$ , and this relationship is robust to different specifications and alternative measures; (2) ${\mathrm{SO}}_2$ emissions can be reduced to achieve reduction targets by forcing companies to strengthen the degree of process production controls and end-of-pipe treatment; (3) eastern and western cities have a better pollution control effect than the other regions, and large cities have better emission reduction effects than smaller cities. Overall, this paper sorts out the evolution of China’s pollution charge policy, and reveals the mechanisms behind the real effects of pollution charges reform on ${\mathrm{SO}}_2$ emissions, thus providing timely implications for policymakers concerned with environmental protection.