Municipal amalgamation is one of the core policy tools for Chinese government intervention in urbanization. The city-county merger policy provides a valuable research object for examining whether government-led urban expansion improves the quality of public services. By using city panel data from 2003 to 2019, this paper examines the policy effects of city-county mergers on the quality of public services using the Propensity Score Matching-Difference-in-Differences (PSM-DID) model. The results indicate that, after controlling for other factors, city-county mergers have increased the quality of public services by 1.2%. A placebo test has validated the robustness of this positive effect. Through further tests, the paper finds that the policy has positively affected all three aspects of the quality of public services in China: education, health care, and transport infrastructure, with the greatest impact being on education. Using a case study of a city-county merger in the Fenghua District of Ningbo, this paper depicts the transmission mechanism and argues that the policy affects the quality of public services by providing institutional security (financial and administrative power) and promoting regional integration in the new city area.

A low-carbon city policy (LCC) is a comprehensive environmental regulation to promote urban green development and resolve the overcapacity contradiction. This study uses China’s low-carbon city pilot policy as a “quasi-natural experiment” based on a panel of 266 Chinese cities, covering three batches of low-carbon pilot cities from 2003 to 2019. We measure industrial capacity utilization at the city level and then construct a time-varying DID (TV-DID) model to investigate the effect of a low-carbon city policy on industrial capacity utilization in Chinese cities, exploring the mechanism, heterogeneity, and spatial effects. It is found that (1) LCC improves industrial capacity utilization by approximately 3.2%, and the above finding still holds after a series of robustness tests, such as the parallel trend test, PSM-DID, DDD, and placebo test. (2) LCC improves industrial capacity utilization through three channels: alleviating resource misallocation, promoting industrial structure upgrading, and stimulating technological innovation. (3) The improvement of LCC on industrial capacity utilization has heterogeneity and positive spatial spillover effect. (4) The heterogeneity analysis shows that the improvement of LCC on industrial capacity utilization is stronger in cities in the high quartile of industrial capacity utilization, cities in old industrial bases, cities along the “Belt and Road” route, and cities in a free-trade zone. The theoretical analysis and empirical results of this study provide empirical support for the promotion of low-carbon city policy globally and provide ideas for solving the overcapacity contradiction in the context of global decarbonization.