Does China's low-carbon city pilot policy improve energy efficiency?

The execution of the low-carbon city pilot strategy by the Chinese government is an essential assurance for optimizing the urban ecological environment and the key to enhancing energy efficiency. Based on the panel data of 199 prefecture-level cities in China from 2003 to 2016, the propensity score matching and difference-indifferences (PSM-DID) model was used to empirically validate the influence of the low-carbon city pilot policy on energy efficiency, and its internal mechanism was further analyzed. The study findings demonstrated that: (1) Low-carbon city pilot policy tremendously increased the level of energy efficiency; however, there was a lag in the impact of policy implementation. (2) The heterogeneity study of cities demonstrated that the low-carbon city pilot policy had a highly diverse influence on the energy efficiency of various types of cities. More specifically, the low-carbon city pilot program had a more noticeable influence on the energy efficiency improvement of big cities, non-resource cities, and eastern cities compared with small and medium-sized cities, resource cities, and central and western cities. (3) The analysis of the impact mechanism revealed that the low-carbon city pilot policy improved energy efficiency through industrial structure optimization and technological innovation, while energy consumption has not been established as an effective approach for low-carbon city pilot policy to affect energy efficiency.