Reducing supply chain carbon emissions in consideration of energy service companies under the cap-and-trade mechanism

In this study, we investigate a supply chain consisting of a supplier, a manufacturer, and a third-party energy service company under three types of emission reduction modes, namely, independent emission reduction mode, third-party contract mode, and supplier contract mode. By solving game-theoretic models, the manufacturer’s optimal choice for abatement modes is explored and the impacts of different modes on firms are analyzed. Considering consumers’ low-carbon awareness, the changes in equilibrium strategies and consumer surplus are also analyzed through mode comparisons and numerical simulations. Furthermore, this study extends the supplier contract mode to the case of independent decisions by the supplier’s internal business departments. The findings are summarized as follows: First, in the supplier contract mode, the unit abatement level is higher than in the third-party contract mode; the size of the unit abatement level under the independent emission reduction mode and both contract modes varies in different threshold intervals. Second, if the cost difference coefficient is low, both the supplier and the manufacturer can achieve a win–win situation under the independent abatement scenario. Third, in the supplier contract mode, the profits of both supplier and manufacturer are not affected by the sharing ratio but in the third-party contract mode, they fluctuate with the sharing ratio. Fourth, under certain conditions, independent decisions by the internal business department of the supplier can create high profits.