Environmental regulation and energy-environmental performance-Empirical evidence from China's non-ferrous metals industry

Environmental regulation (ER) is regarded as an important driver of environmental improvement. Taking China's non-ferrous metals industry (NFMI) as a sample, this paper discusses the relationship between ER and energy environmental performance (EEPI) in two stages, and tests the effectiveness of the strong Porter hypothesis. In the first stage, this paper uses the global environment DEA to construct the competitiveness index, EEPI, which represents green development. In the second stage, we explore the relationship between two types of ER and EEPI by using the panel Tobit model and considers the non-linear characteristics of ER and regional heterogeneity. Moreover, a mechanism analysis is conducted. The results show that: (1) at a reasonable regulatory level, this study supports the strong Porter hypothesis in China's NFMI. (2) Technological innovation plays a mediating effect between environmental regulation and EEPI. (3) From a national perspective, there is a significant inverted U-shaped non-linear relationship between environmental expenditure and EEPI, and a significant U-shaped non-linear relationship between environmental investment and EEPI. (4) Regional samples present heterogeneous results between ER and EEPI. Based on the conclusions, we believe that environmental regulation policies should take into account regional differences and incorporate diversified green innovations to achieve sustainable development.