Abstract: As China continues advancing the construction of eco-civilization, promoting emissions abatement collaboration in supply chains has become an important measure in practicing green development concept in production and consumption domains. However, in green supply chain management different types of core enterprises have different development objectives and business strategies so that supply chain power structure has become a key factor in emissions abatement decision-making. In this paper, a two-echelon supply chain that consists of two manufacturers and one retailer is investigated, in which the manufacturers decide the emissions abatement levels of their products whereas the retailer decides the retail prices of the products. A Stackelberg-Nash game is characterized and the equilibrium solutions are derived for both the case where the manufacturers are the duopoly supply chain leaders and the case where the retailer is the monopoly supply chain leader.In both cases, the game model consists of two sub-games:a vertical leader-follower Stackelberg game between the manufacturers and the retailer, and a horizontal Nash game between the two manufacturers.Numerical experiments using representative data from real industry datasets and some manipulated datasets in related literature are conducted to examine the impacts of production cost, wholesale price and carbon tax rate on the optimal emissions abatement and pricing decisions.Based on these theoretical results, it is shown that:under two types of supply chain structures, (1) when the wholesale price is fixed, decreasing the unit production cost will increase the manufacturers' optimal emissions abatement levels; however, when the unit production cost is fixed, increasing the wholesale price will not always lead to an increase in emissions abatement levels; (2) for manufacturers who have low baseline emissions, increasing carbon tax rate will increase their optimal emissions abatement levels, while for manufacturers who have high baseline emissions, increasing carbon tax rate will decrease their optimal emissions abatement levels unexpectedly; (3) in general, the optimal emissions abatement levels and total supply chain profit are relatively higher and the total carbon emissions is relatively lower when the retailer is the supply chain leader. Finally, it is found that with the increase of wholesale price, double marginalization has been intensified under both the two supply chain power structures. However,according to the numerical results it is suggested that within a certain range of carbon tax rate, the optimal emissions abatement levels and total carbon emissions under both the two supply chain power structures are better off when compared with the supply chain centralized case due to the existence of double marginalization. Inthis research,some useful managerial insights are developed for emissions abatement collaboration in supply chains under carbon tax policies.

Key words: green supply chain, carbon emissions, power structure, game theory