Can Low-Carbon Pilot City Policies Effectively Promote High-Quality Urban Economic Development?—Quasi-Natural Experiments Based on 227 Cities

To explore the relationship between low-carbon pilot city policies (LCC) and the high-quality development of urban economy, this paper calculates the high-quality development index based on five dimensions to construct a double-difference model for empirical research, taking the data of 227 cities in China from 2004 to 2019 and the second batch of low-carbon pilot cities as the main research object. The research conclusions are as follows: (1) The LCC has promoted the high-quality economic development of the pilot cities, and has long-term effects, which are mainly reflected in three dimensions: Innovative development, residents’ life, and urban public services. (2) The promotion effect is mainly reflected in the big cities, as well as the eastern and central regions. (3) The intermediary function is embodied in three aspects: Industrial upgrading, urban technological innovation, and urban investment