Regional disparities and inadequate development remain key obstacles to achieving common prosperity in China. In the new era, the implementation of initiatives such as the coordinated development of the Beijing-Tianjin-Hebei region and the development of the Yangtze River Economic Belt has provided crucial opportunities to narrow regional gaps and promote integrated national development. A systematic assessment of the common prosperity effects of major national strategic zone construction (MNSZC) holds significant theoretical and practical value for advancing the Chinese path to modernization.

Based on panel data from 280 cities in China from 2008 to 2022, this paper constructs a multi-period DID model to examine the impact of MNSZC on common prosperity and its underlying mechanisms. The findings reveal that MNSZC significantly promotes common prosperity. Mechanism testing indicates that MNSZC enhances the interregional mobility of labor, capital, and technology, and simultaneously activates structural, scale, and technological effects within regions. These dynamics accelerate the formation of a complementary and high-quality regional economic structure, effectively advancing common prosperity. Heterogeneity analysis suggests that the positive impact of MNSZC is more pronounced in regions with higher administrative levels, urbanization rates, and degrees of marketization. Sub-regional analysis further indicates that the effects are particularly significant in strategies such as the coordinated development of the Beijing-Tianjin-Hebei region, the development of the Yangtze River Economic Belt, and the Yangtze River Delta integration.

This paper makes the following marginal contributions: First, it evaluates the role of MNSZC in promoting common prosperity within the context of regional coordination and the Chinese path to modernization, thereby expanding the research perspective on how regional development policies contribute to common prosperity. Second, it enriches the theoretical framework by analyzing the internal mechanisms through which MNSZC drives a complementary and high-quality regional economic layout. Third, by identifying the heterogeneous effects across administrative hierarchy, urbanization, and marketization, and conducting subgroup analyses of key strategic regions, it provides empirical support and policy references for enhancing the precision and coordination of regional strategies.