Research on the regional synergistic effects of carbon and pollution reduction from a value perspective

Against the backdrop of "dual carbon", systematically identifying the synergistic effects of carbon and pollution reduction from a value perspective and their spatial transmission is essential for promoting green transformation. Based on Chinese provincial panel data from 2005 to 2023, this paper first employs a dual model to measure the marginal abatement cost of carbon and pollution under individual and joint abatement scenarios. Then, the regional synergistic effects of carbon and pollution reduction are calculated from the value perspective. Finally, a spatial correlation network through the modified gravity model is constructed, revealing corresponding spatial correlation characteristics from the overall, individual, and block model characteristics. The findings show that, firstly, joint abatement significantly reduces the marginal abatement cost of carbon and pollution, and the cost-saving advantage continues to expand, with the abatement constraint accelerating its shift from pollution reduction toward carbon reduction. Secondly, the regional synergistic effect level demonstrates the characteristics of phased evolution, significant heterogeneity, and imbalanced sub-item synergy, with the pace of carbon reduction lagging behind that of pollution reduction. Thus, region-specific measures should be adopted to address weaknesses in sub-item synergy and accelerate the carbon reduction process. Thirdly, the spatial correlation network of the regional synergistic effects shows a gradually optimized structure, clear core-periphery differentiation, and increasingly directional inter-block transmission, accompanied by substantial regional heterogeneity and differentiated block functions. Therefore, cross-regional coordinated governance and network coordination mechanisms should be improved. This paper deepens the understanding of the value implications and spatial correlation patterns of regional synergistic effects of carbon and pollution reduction in China and provides potential methodological insights for economies facing multiple environmental constraints to pursue coordinated governance.