Abstract: Considering the supply chain composed of a single manufacturer and a single platform, where the manufacturer implements the emission reduction strategies and the platform fulfills CSR(corporate social responsibility), the Stackelberg game models between manufacturer and platform are built under four combination cases that the government subsidizes the manufacturer based on the R&D cost for emission reduction and based on the low-carbon production, and the platform supply chain adopts the wholesale mode and the agency mode, respectively, together with the optimal pricing and emission reduction decisions of the supply chain by solving the models. Based on comparative analysis, the optimal subsidy strategy of the government and the optimal sales model of the platform supply chain are obtained. Through numerical simulation, we analyze the impacts of the subsidy coefficient, consumers low-carbon preference, platforms fulfillment of CSR, and low-carbon promotional efforts on the supply chains decision-making and social welfare under the two subsidy modes. The research shows that: the level of carbon emission reduction, the total profit of manufacturers and supply chain, the degree of environmental improvement and the level of social welfare are higher in the agency mode than in the wholesale mode. In the wholesale model, the retail price of low-carbon products and platform profits are higher. The subsidy strategy based on the low-carbon production is more conductive to increasing manufacturers profits, while the strategy based on emission reduction cost is more favorable to platforms profits. From the dimensions of improving the level of carbon emission reduction, the degree of environmental improvement and the level of social welfare, the subsidy strategy based on the R&D cost is optimal strategy of government, and the improvement of the level of social welfare is more significant under the subsidy strategy based on the low-carbon production.

Key words: government subsidies, carbon emission reduction, platform sales mode, stackelberg model, corporate social responsibility