Water Quality and Economic Growth in the Yellow River Basin: An Empirical Study Based on the Environmental Kuznets Curve (EKC) and Night Lights

The relationship between the environment and economic growth has always been valued by scholars, and research on them can provide references and opinions for economic development while taking into account environmental protection. The EKC has also been extensively studied in different regions and pollutants. However, there are few studies on water pollution and the Yellow River Basin. Therefore, this article takes 9 provinces (autonomous regions) in the Yellow River Basin as the research object, selects the main pollutants in the basin (COD) as the water pollution indicator, uses the night light data as the economic growth indicator to perform OLS regression and uses the instrumental variable method and replace the standardized benchmark as robustness tests. Finally, another kind of water pollution, NH3-N, was discussed. The results show that there is a positive U-shaped curve between COD and economic growth, and an N-shaped curve between NH3-N and economic growth. There is no EKC. The contribution of this research lies in the use of night lights instead of traditional GDP as an indicator of economic growth, the selection of appropriate instrumental variables, and the discovery of problems with the statistical caliber of China’s water pollution data.