The contradiction between industrial economic development and the ecological environment in Northwest China is prominent, so the green transformation of industrial economy in this region is imperative. From the perspective of industrial ecology, this study uses economic and environmental statistics from Northwest China from 2006 to 2018 as well as the Krugman specialization index and entropy index methods to calculate the degree of different types of industrial agglomeration in Northwest China. The eco-efficiency of Northwest China is calculated by the global SBM-DDF model. On this basis, the stochastic effect panel tobit regression model is used to analyze the influence and mechanism of different types of industrial agglomeration on eco-efficiency in Northwest China. The results show that the concentration of specialization has a significantly negative effect on the eco-efficiency of Northwest China at the level of 1%. Excepting Ningxia, the eco-efficiency of other provinces has been improved with the decrease of industrial specialization. The influence of the related diversification agglomeration on the eco-efficiency in Northwest China shows a U curve. The degree of industrial correlation diversification in Qinghai and Ningxia is less than the critical value 1.45, whereas Shaanxi, Gansu, and Xinjiang have crossed the inflection point. The unrelated diversification agglomeration has a negative effect on the eco-efficiency of Northwest China at the level of 1%, and the degree of industrial independent diversification in Shaanxi Province has decreased slightly, which is beneficial to the improvement of eco-efficiency. By contrast, other provinces have increased considerably. The conclusion can provide a theoretical basis for industrial green transformation path selection and related policy formulation in Northwest China.

Southwest China is a fragile terrestrial ecosystem restricted by its geological background, which leads to a contradiction between its industrial economic development and the ecological environment. In this study, to explore the influence and mechanisms of the three industrial agglomeration modes, namely, specialization, related diversification, and unrelated diversification, on the eco-efficiency of the region, linear and nonlinear regression models were applied to the data of five Southwest provinces from 2006 to 2018. Specialization agglomeration had a significant negative impact on the eco-efficiency of four provinces outside Tibet in Southwest China. With the decrease of industrial specialization, their eco-efficiency improved. The effects of related diversification agglomeration on the ecological efficiency of four provinces outside Tibet in Southwest China showed a “U” curve. The degree of industrial diversification in these provinces exceeded the critical value of 1.46, and the effect on eco-efficiency was shown. The unrelated diversification agglomeration had a negative effect on the ecological efficiency of the four provinces outside Tibet in Southwest China. The degree of industrial-unrelated diversification in Guizhou Province increased slightly, which was not conducive to the improvement of local eco-efficiency. Additionally, it decreased significantly in other provinces, which caused the improvement of local eco-efficiency. The conclusion provides a theoretical basis for industrial green transformation path selection and related policy formulation in Southwest China.

In this study, we used the super-efficient global slacks-based measure of directional distance functions (SBM-DDF) model to evaluate the ecological efficiency and changes in 12 provinces in western China between 2006 and 2020. We then used two linear and nonlinear regression models to analyze in detail the influence mechanisms of different industrial agglomeration forms on the local ecological efficiency. The results show the following: the overall ecological efficiency in the western China region shows a dynamic upward trend. The ecological efficiency of western China is quite different, with the overall characteristics of “high in south and low in north”, “slow in south and fast in north”, and “three-way polarization.” Different types of industrial agglomeration in western China have obvious differences in terms of ecological efficiency. Both specialized agglomeration and unrelated diversification agglomeration in western China have a significant negative impact on ecological efficiency. The relationship between agglomeration-related diversity and ecological efficiency in the western region is of the “U” type. This study’s results can also provide a reference for the formulation of industrial transformation and ecological protection policies in the implementation process of the second round of the western development strategy. This study thus has fundamental significance in the promotion of the second round of western development work.