Study on Cooperative Game and Cost Sharing of PM2.5 Reduction in Beijing, Tianjin, and Hebei

The Beijing–Tianjin–Hebei (BTH) region is one of the most complex and heterogeneous regions in China, where differences in marginal abatement costs across cities jointly shape the effectiveness of regional air quality management. This study develops an integrated analytical framework that combines pollutant-specific abatement cost accounting, optimization of territorial and coordinated emission reduction scenarios, and cooperative game-based cost allocation. Using this framework, we quantify both the total cost-saving potential and the distributional effects of coordinated air pollution control in the BTH region. The results are as follows: (1) Under the territorial governance model, the total cost reaches CNY 22.627 billion, whereas coordinated governance lowers this to CNY 21.647 billion. Joint prevention and control is economically more efficient and produces a globally optimal cost outcome for the region. (2) After redistribution, the final burdens of Beijing (CNY 572 million), Tianjin (CNY 1.154 billion), and Hebei (CNY 19.921 billion) are all lower than their territorial governance costs, ensuring that each region gains from cooperation. (3) Significant differences in marginal removal costs among the three regions, with Hebei exhibiting the highest marginal emission cost and lowest marginal removal cost. Optimal coordinated governance requires Hebei to undertake a greater share of emission reduction, while Beijing and Tianjin reduce less compared with their independent plans. The coordinated model enhances regional resource efficiency, reduces redundant investment, and achieves the same total emission reduction at a lower aggregated cost.