In this paper, panel data from nineteen key cities in the Sichuan–Chongqing urban agglomeration from 2003 to 2016 were used as the study sample. Using the stochastic impacts by regression on population, affluence, and technology (STIRPAT) model, the effect of foreign direct investment (FDI) on particulate matter (PM_2.5) pollution and its action mechanism in the Sichuan–Chongqing urban agglomeration were considered for both socioeconomic and natural factors. The results showed that the “pollution halo” hypothesis of FDI in the Sichuan–Chongqing urban agglomeration has been supported. There are significant positive spatial spillover effects of PM_2.5 pollution in this urban agglomeration, and the introduction of FDI is conducive to alleviating PM_2.5 pollution in the urban agglomeration. Similar to the “inverted U” curve proposed by the environmental Kuznets curve (EKC) hypothesis, there was a significant “inverted U” curve relationship between PM_2.5 pollution and economic growth in the Sichuan–Chongqing urban agglomeration. However, there was a significant “U”-type curve relationship between the urbanization degree and the PM_2.5 concentration, which indicates that the current urbanization mode may aggravate the pollution degree of PM_2.5 in the urban agglomeration in the long term. Furthermore, the two natural factors of annual average temperature and annual precipitation play an important role in PM_2.5 pollution and spatial spillover effect in the Sichuan–Chongqing urban agglomeration. Economic development and rationalization of the industrial structure are the main ways by which FDI affects PM_2.5 pollution in the urban agglomeration. The research conclusions of this study can be of great practical significance to optimize the regional industrial layout, control PM_2.5 pollution, and establish a sustainable development policy system in the Sichuan–Chongqing urban agglomeration.

With the rapid growth of foreign direct investment (FDI), PM_2.5 pollution in Chinese cities is increasing. Based on panel data for 271 Chinese cities from 2003 to 2016, this paper uses the dynamic spatial fixed-effects Durbin model to analyze the correlation between FDI and PM_2.5 pollution and the effect of FDI on urban PM_2.5 concentrations, as mediated by industrial structure transformation, which is clarified using Stata/SE 16.0. The results showed that PM_2.5 pollution in China has significant spatial spillover effects, and the pollution haven hypothesis is applicable to Chinese cities. The industrial structure partially mediates the relationship between FDI and PM_2.5. This paper proposes that local governments should promote the market-oriented reform of FDI to create a more convenient, legalized, and international environment for FDI and innovate the governance philosophy of only reducing the existing emissions. A top-level design and sound market supervision system of PM_2.5 control are also needed.

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.

In recent years, trade protectionism and unilateralism have prevailed, and countries around the world have imposed restrictions on log exports. It has also become more difficult for China to import wood resources and export deep-processed wood forest products. Based on panel data from 2000 to 2019, this study uses social network analysis to measure the level of the Chinese wood forest product trade network, takes the Chinese free trade agreements (FTAs) as the natural experiment, and uses the multi-stage double-difference method to investigate the impact of the signed FTAs on China’s wood forest product trade. The study finds that the trade network of Chinese wood forest products is becoming increasingly complex, and the central position of China and the Association of Southeast Asian Nations (ASEAN) in the network is increasing year by year. The signing of FTAs has had a significant positive impact on the trade of wood forest products in China and a significant trade creation effect. This finding remains true after conducting the placebo test and propensity score-matched regression control. At the same time, the import of wood forest products in China will have a significant trade transfer effect due to the signing of FTAs, and this will not affect exports. Although FTAs show significant trade creation and trade transfer effects in China’s wood forest product trade, they also increase, to a certain extent, the mismatch of forest resources worldwide.