China's high-speed rail (HSR) construction provides an ideal ‘quasi-natural experiment’ in which regional issues are investigated. This study explores how HSR affects innovation efficiency and explores the mediating effect of urban form. Based on panel data comprising 280 cities in China from 2006 to 2016, this study uses a time-varying difference-in-differences method to analyze whether HSR affects regional innovation, and it explores the mediating effect of urban form. The results show the following. (1) HSR significantly promotes regional innovation. The parallel trend test shows that the treatment group and the control group have the same trend before HSR construction. (2) Knowledge spillovers are important manifestations through which HSR promotes regional innovation. HSR can significantly improve the level of total factor productivity and human capital. (3) Urban form mediates the impact of HSR on regional innovation significantly, which varies across the different indexes of different urban forms.

With rapid economic development, the protection of the ecological environment has become very important. The modernization of rural ecological governance is the basis and prerequisite for the sustainable economic and social development of vast rural areas of China in the current era. It is urgent to analyze the influencing factors and to improve China’s rural ecological environment governance efficiency for Rural Revitalization in the new era, and to promote the modernization of the national environmental governance system and governance capacity. This paper empirically examines the influencing factors on rural ecological environment governance efficiency in the whole country, and in the eastern, central and western regions separately, at the provincial level, using the Tobit regression model. The results show that, at the national scale, the level of rural economic development, the size of village committees and rural public participation all have positive roles in promoting the efficiency of rural ecological environment governance. Rural population agglomeration, financial support for agriculture. And environmental protection social organizations have negative roles, hindering the efficiency of rural ecological environment governance. From the perspective of the eastern, central, and western regions, the factors affecting the efficiency of rural ecological environment governance are different due to regional differences. According to the results of empirical analysis, it is proposed that the key issue in improving the efficiency of rural ecological environment governance in China is to promote differentiated regional coordinated governance mechanisms.

The Party’s 14th Five-Year-Plan and the 2035 Visionary Goals point out that green and sustainable development is the direction of China’s road in the present age, and provide a theoretical basis for further improvement of ecological civilization. “Sponge city” is a new type of urban construction idea in China; moving from pilot to vigorous implementation at present, it is an important element of China’s promotion of green development and development of ecological civilization. At present, a number of sponge city pilot projects have been built in China, and evaluation of their effects is already a matter of urgency. The overall planning of China’s current policies in sponge city construction and the specific analyses conducted by experts from both subjective and objective aspects have not been able to completely fill the gap in this regard, thus making it particularly urgent to conduct in-depth studies. Based on this, this paper discusses the performance assessment of sponge cities in China on the basis of the prediction and analysis of the development trend of sponge cities in China. In the performance assessment system, the correctness and timeliness of the index system should be considered in terms of practical effects; in the city performance assessment, the ideas of new city development such as low-carbon cities and smart cities should be combined to build a comprehensive and multi-perspective intelligent assessment system, so as to provide a strong boost to promote the development of city construction and its evaluative research. Firstly, a system-dynamic model is applied to sort out and combine its internal operation mechanism, and a set of evaluation systems based on the ecological philosophical perspective of the sponge city and urban sustainable development performance is established. Second, to improve the accuracy of the research results, parallelism tests and robustness analysis were conducted on this performance index evaluation system. The study’s results show that sponge city construction has achieved good results in sustainable urban development and has contributed to future development.

The question of how to proactively respond to population aging has become a major global issue. As a country with the largest elderly population in the world, China suffers a stronger shock from population aging, which makes it more urgent to transform its industrial and economic development model. Concretely, in the context of the new macroeconomic environment that has undergone profound changes, the shock of population aging makes the traditional industrial structure upgrading model (driven by large-scale factor inputs, imitation innovation and low-cost technological progress, and strong external demand) more unsustainable, and China has an urgent need to transform it to a more sustainable one. Only with an in-depth analysis of the influence mechanism of population aging on the upgrading of industrial structure can we better promote industrial structure upgrading under the impact of population aging. Therefore, six MSVAR models were constructed from each environmental perspective based on data from 1987 to 2021. The probabilities of regime transition figures show that the influencing mechanisms have a clear two-regime feature from any view; specifically, the omnidirectional environmental transition occurs in 2019. A further impulse–response analysis shows that, comparatively speaking, under the new environment regime the acceleration of population aging (1) aggravates the labor shortage, thus narrowing the industrial structure upgrading ranges; (2) has a negative, rather than positive, impact on the capital stock, but leads to a cumulative increase in industrial structure upgrading; (3) forces weaker technological progress, but further leads to a stronger impact on the industrial structure upgrading; (4) forces greater consumption upgrading, which further weakens industrial structure upgrading; (5) narrows rather than expands the upgrading of investment and industrial structures; and (6) narrows the upgrading of export and industrial structures. Therefore, we should collaboratively promote industrial structure upgrading from the supply side relying heavily on independent innovation and talent, and the demand side relying heavily on the upgrading of domestic consumption and exports.

In an era of global economic slowdown, effectively stimulating urban economic development has become a critical challenge for governments around the world. Based on the panel data of 280 prefecture-level cities in China from 2006 to 2017, this study adopts the double-difference method to evaluate the impacts of innovative cities pilot policies on urban economic growth, explore the mechanism through the intermediary effect model, and study the heterogeneity of cities with different development endowments by sub-samples. This study shows the following: (1) The policy of innovative pilot cities has significantly promoted their economic growth: GDP growth rates in the pilot cities are 1.14 percent higher than those in non-pilot cities. (2) The innovative city policy can effectively improve technological progress and human capital, thereby promoting economic growth. (3) The promotion effect of the pilot policy on the economy varies by region, city size, administration grade, market level, and government efficiency. Specifically, the policies have the most substantial positive effects in cities with lower administrative levels, smaller sizes, less market orientation, and higher government efficiency. This research, based on the city data from the world’s largest economy, evaluates the impact of government intervention—targeted urban innovation policies—on economic development, providing valuable insights into how innovation policies can be tailored and optimized for diverse urban contexts.

Taking 286 cities above the prefecture level in China as the research object and the research period from 2003 to 2019, through the two-way fixed effect model, this paper empirically analyzes the impact of the city level on environmental collaborative governance. The threshold regression model is used to reveal the nonlinear relationship between urban levels and environmental collaborative governance and to analyze the phase characteristics of different urban levels for environmental collaborative governance. The results show that: (1) The city level has a significant role in promoting collaborative environmental governance. (2) The regression results of the three major sections show that the urban level promotion in the eastern region has the strongest promoting effect on the coordinated environmental governance, and the western region is the weakest. (3) The impact of the city level on collaborative environmental governance is nonlinear. When the city scale reaches a certain critical point, its impact on the collaborative environmental governance tends to intensify.