Sequential growth of urban environmental efficiency: evidence from Chinese cities

We examined the relationship between city size and environmental efficiency and found sequential growth of environmental efficiency in 282 Chinese cities from 2003 to 2019 and also tested the mechanism of industrial transfer. The empirical results show that as the period advances, the relationship between the environmental efficiency of cities and the city size changes from an upward-sloping straight line to a "U-shaped" structure, indicating that the urbanization advantages of megacities are shifting to large or medium-sized cities. This shift is the result of the industrial transfer. The government should refrain from excessive market interventions in industrial shifts. Simultaneously, it should facilitate population mobility in large cities and enhance public services for medium-sized cities. Small cities undergoing population decline should not be hindered.