As an underdeveloped and low-income region, the development of minority regions in Northwest China is crucial. As an important part of minority regions, Ningxia Hui Autonomous Region has insufficient endogenous power for stable economic development and high risk of returning to poverty. On the whole, the Ningxia county network shows a spatial pattern of high in the north and low in the south. However, there are great differences in the centrality of different factor flow networks. The factor connections between most counties are weak, and a close innovation network has not yet been formed. There is an obvious administrative clique structure, showing a certain degree of self-enclosure. The factor flows between counties are relatively uniform and greatly affected by geographic distance. From the perspective of integrated flow, the Ningxia county network presents a distinct core-periphery circle structure. Population size and GDP are the main factors affecting the spatial network. The policy implication of this study is that Ningxia Autonomous Prefecture should coordinate the planning of the region’s economy, technology, and transportation, so as to reduce the development gap between counties by enhancing the closeness of the county spatial association network, and ultimately realize the region’s high-quality development.

Free trade zones (FTZ) are designated areas for promoting trade openness and investment facilitation. In China, FTZs are also regarded as “green areas” in which planning actions and institutional innovations are implemented, and there is a commitment to promoting urban green and healthy development. Given that green total factor productivity (GTFP) is an important measure of a city’s health and green performance, this study exploits the difference-in-differences method to explore the impact of pilot FTZs on urban GTFP in 280 cities in China for the period between 2005 and 2017. The results show that the green areas positively contributed to the growth of GTFP. Moreover, the outcome holds with robustness tests. Statistically, the positive effect emerged in cities during the first three years after introducing the initiative, with the effect disappearing afterward. It also had a strong positive impact in the central and western regions and in large and medium-sized cities, while the influence remained insignificant in the remaining areas in China. Furthermore, the paper also reveals that the promotion of foreign direct investment and industrial structure upgrading are the primary channels through which the positive relationship between pilot FTZs and GTFP is established.

With the green, circular, and low-carbon concept, eco-industrial parks are regarded as key drivers for maximizing environmental and economic benefits. Based on the panel data of 276 cities in China from 2007 to 2018, this paper regards the establishment of eco-industrial parks as a quasi-natural experiment, and employs the difference-in-differences method to test the impact of eco-industrial parks on urban haze pollution. We find that eco-industrial parks significantly reduce urban haze pollution and the conclusion holds with robustness tests. Heterogeneity analysis shows that the effect of eco-industrial parks on haze pollution is more pronounced in eastern and resource-based cities. Finally, mechanism analysis indicates that eco-industrial parks reduce urban haze pollution mainly by promoting technological innovation, upgrading industrial structure, and strengthening urban environmental regulations.

The international community has reached a consensus on preventing the global climate from deterioration. As the country with the largest carbon dioxide emissions, China has made a commitment to such prevention. Free trade zone (FTZ) established in 2013 is a designated area planned for promoting trade openness and investment facilitation. More importantly, it is a policy experiment aimed at establishing a green and low-carbon development model. Based on province-level data of China for the period 1997-2017, this study exploits the synthetic control method to explore the impact of FTZ policy on carbon dioxide emissions. The results show that, compared with the synthetic control regions, the carbon dioxide emission of the Shanghai FTZ has reduced by about 10% after the implementation of the FTZ policy. Moreover, the outcome holds with placebo tests and sensitivity analysis. Employing the difference-in-differences method, the results also demonstrate FTZ policy substantially reduces carbon dioxide emissions. Our findings provide institutional enlightenments for China and other developing countries to balance economic development and environmental protection with opening to the outside world.