City size and energy conservation: Do large cities in China consume more energy?

Although the nexus between urbanization and energy consumption has been widely discussed at the macro level or in specific areas such as in relation to residents and transport, how the expansion of city size affects energy consumption in the process of urbanization is still unknown. Clarifying this impact mechanism is necessary for China to achieve its energy conservation goals. In this context, based on a systematic theoretical elaboration, this study constructs an econometric model of the nexus between city size and energy use and performs a series of robust empirical analyses through the endogenous control of instrumental variables. The results show that the current expansion of China's city size tends to positively affect energy consumption; however, as city size continues to expand, energy consumption will exceed the critical value and change from increasing to decreasing. In this process, it is easier to achieve a decline in energy intensity than a decline in per capita energy consumption. Cities with a population exceeding 1 million in their urban districts are more conducive to reducing energy use. Compared with the expansion of urban built-up areas, an increasing population agglomeration can more effectively promote the decline of urban energy consumption. This study provides policy makers with new ideas about urban planning and energy conservation.