This paper develops a quantitative spatial equilibrium model incorporating industrial subsidies, establishing an intrinsic linkage between the unified national market and local industrial policy competition. It quantitatively analyzes the impact of local industrial policy competition on real economic growth and other outcomes. The findings are as follows. Firstly, when the degree of market integration is low, local industrial policy competition is more conducive to economic growth and the improvement of aggregate welfare. When the degree of market integration is high, the central industrial policy proves to be superior. Among them, the reduction of trade costs is the main reason. The reduction of population mobility costs has little impact on industrial policy, but it is conducive to exerting the scale economy effect of the market, improving aggregate welfare, and reducing inter-regional income inequality. Secondly, under the unified national market, due to the scale economy effect, the market gradually plays a decisive role, while the subsidy effect decreases. Thirdly, the transfer payment from the central government does not play a role in regulating local industrial policy competition on the whole. In addition, transfer payment and industrial policy cooperation can both promote economic growth and contribute to coordinated regional development, which is conducive to achieving more efficient equity. Fourthly, local industrial policy cooperation has propelled economic growth through economies of scale and the deepening of the division of labor, but to further drive economic growth, it is necessary to make full and better use of the advantages of the super-large market . However, under the unified national market, top-down industrial policies are the most efficient. The analysis in this paper provides insights for understanding local industrial policy competition, promoting the construction of a unified national market, and better leveraging the roles of the market and the government.

Accelerating the building of a unified national market that is efficient, well-regulated, competitive, and fully open will promote the smooth and extensive flow of commodity factors and resources. This provides comprehensive market conditions for enhancing the resilience and security of China’s industrial chains. Analyzing data on domestic market integration across Chinese provinces from 2010 to 2023 and related data on listed enterprises, this paper examines the impact of building a unified national market on industrial chain resilience and its operational mechanisms. The findings indicate that the building of a unified national market significantly enhances the resilience of the upstream, downstream, and overall industrial chains. The underlying mechanisms involve an increase in enterprise total factor productivity and a reduction in production costs. Furthermore, this effect exhibits significant heterogeneity at the provincial, industry, and enterprise levels. Further analysis reveals that increasing technological and credit distances between upstream and downstream enterprises within the industrial chain weaken the positive effect of building a unified national market on industrial chain resilience. Therefore, enterprises ultimately choose to transfer their production collaborations. This paper elucidates the theoretical logic for enhancing industrial chain resilience through the building of a unified national market, offering important insights for developing secure, stable, and resilient industrial chains in China.

Building a unified national market is the foundational support and inherent requirement for establishing a new development pattern. As the underlying architecture and technological foundation of digital China, digital infrastructure provides a new opportunity for accelerating the building of a unified national market. This paper, based on panel data from cities in China from 2009 to 2020, analyzes the impact of digital infrastructure construction on the formation of a unified national market and its mechanisms from both theoretical and empirical perspectives. It also explores the synergistic effect of expanding transportation networks. This paper finds that the construction of digital infrastructure significantly promotes the formation of a unified national market. The enhanced data factor mobility and increased degree of technological specialization brought about by the development of digital infrastructure are important channels affecting the formation of a unified national market. Heterogeneity analysis reveals that in terms of urban characteristics, digital infrastructure more effectively promotes the formation of a unified market in small- and medium-sized cities and coastal cities . In terms of government behavior, an increased focus by the government on digital infrastructure and a reduction in administrative segmentation are more conducive to leveraging the promotional role of digital infrastructure in the formation of a unified national market. Extension analysis demonstrates that the expansion of transportation networks and digital infrastructure can form a synergistic effect, significantly boosting the formation of a unified national market.

In response to changes in both domestic and international development environments, the Central Committee of the Communist Party of China (CPC) has called for vigorously promoting high-standard opening up . This approach is primarily defined by the endogenous driving of high-level factors, coordinated balance between efficiency and security, and the demonstration and guidance role of institutional rules . A diversified spatial layout for regional economic cooperation serves as an effective pathway to high- standard opening up. Since the 18th CPC National Congress, China has accelerated the restructuring of this layout to facilitate a comprehensive, high-standard opening up. The main achievements include a more diversified trade and investment market, large-scale overseas operations by Chinese companies, and significant demonstration effects of China model. However, China still faces challenges such as limited replacement capacity in emerging markets and the need to enhance the self-supporting and risk-controllability of overseas supply chains . To further advance high-standard opening up through restructuring the regional economic cooperation layout, China should proactively promote high-standard regional economic and trade negotiations, stabilize and consolidate its traditional market share, strive to build a circle of friends together under the Belt and Road Initiative, help enhance the capability and vitality of emerging markets, and accelerate adjustments to its outward direct investment strategy to create a self-supporting and risk- controllable overseas supply chain system.

High-standard opening up aims to cultivate new comparative advantages driven by innovation, achieving systemic improvement through the upgrading of export industries and institutional opening up. Building a unified national market aims to break down factor market segmentation and unleash the potential of the super-large-scale market. By reducing transaction costs and facilitating the flow of production factors to high-efficiency enterprises, it leverages the advantages of such a market. Coordinating these two initiatives helps improve the efficiency of factor allocation, foster corporate innovation and productivity, optimize the business environment, and promote the development of markets for new production factors . However, it should be noted that institutional opening up currently faces issues such as lagging institutional supply in emerging sectors. Meanwhile, the building of a unified national market confronts challenges involving inter- departmental, urban-rural, and inter-regional market segmentation, as well as difficulties in developing markets for new production factors. To this end, it is necessary to further deepen reforms comprehensively by properly handling the relationship between the government and the market and breaking down market segmentation barriers, thereby promoting the synergistic development of both and facilitating high-quality economic transformation.