Multiplan Integration Pilot Policy and Urban Low-Carbon Transformation: Microlevel Empirical Evidence from Chinese Listed Companies Based on Difference-in-Differences Analysis

The multiplan integration pilot policy (MIPP) serves as a crucial instrument for establishing spatial planning systems and advancing urban low-carbon transformation. This research treats MIPP implementation as a quasi-natural experiment, utilizing panel data from Chinese cities and listed companies spanning 2007–2021 (sourced primarily from China City Statistical Yearbooks, the CSMAR database, the Wind database, and corporate annual reports) and employing a difference-in-differences model to examine its impact on low-carbon transformation of enterprises (LCTE) and underlying mechanisms. Research findings demonstrate that MIPP significantly promotes LCTE, with various robustness checks further validating this conclusion. Mechanism analysis reveals that MIPP primarily drives LCTE by fostering green technological innovation and alleviating enterprise financing constraints. Heterogeneity analysis indicates that at the city level, compared to northern cities, small-to-medium cities, resource-based cities, smart cities, and innovation-oriented cities, MIPP more effectively facilitates LCTE in southern cities, metropolitan areas, nonresource-based cities, nonsmart cities, and noninnovation-oriented cities. At the enterprise level, MIPP more effectively promotes low-carbon transformation in companies with higher existing transformation levels compared to those with lower levels and more effectively advances transformation in state-owned enterprises and technology-intensive companies compared to nonstate-owned enterprises, labor-intensive enterprises, and capital-intensive enterprises. These findings provide adaptable frameworks for global urban planners, offering evidence-based tools like cross-departmental coordination, differentiated land classification, and spatial clustering to support low-carbon transformation and sustainable development tailored to diverse urban contexts.