The role of population agglomeration played in China's carbon intensity: A city-level analysis

Population agglomeration is an important foundation for urban development, and continuous reductions in carbon emissions need to be considered by urban development planners. However, there is an intrinsic link between population agglomeration and carbon emissions, and only a few studies have discussed this important topic. This study examines how population agglomeration affects carbon intensity using a panel dataset of 272 Chinese cities (2004-2017). Our empirical findings suggest that population agglomeration can effectively reduce carbon intensity. This holds true after a full endogeneity discussion and a range of robustness tests. Meanwhile, the two-step mechanism analysis shows that service industry agglomeration, industrial structure optimisation, and green technology innovation are three important channels for population agglomeration for cutting carbon intensity. The heterogeneity analysis indicates that the effects of population agglomeration on carbon intensity vary across different periods and regions. Valuable information to enable the reduction of carbon intensity is presented from the perspective of population agglomeration.