关键词: 绿色创新, 促销, 能源效率水平, 回收量, 双边成本分担契约

Abstract: The green innovation is an effective means to improve the product energy efficiency level, and the closed-loop supply chain management can reduce the dependence on original resources and effectively save production costs through the recovery and reuse of resources. The combination of green innovation and closed-loop supply chain can effectively reduce the environmental pollution and resource consumption of products in the whole life cycle, which is more conducive to environmental protection and sustainable development. It should be noted that the production of sustainable products and the processing of recycled products are more complex than traditional products, which means that the green innovation has potential positive and negative impacts on decision-making operations of closed-loop supply chain. Therefore, optimizing operation decisions of closed-loop supply chain by distinguishing between the positive and negative aspects of green innovation is key to pursuing sustainability.
   In this paper, a two-level closed-loop supply chain consisting of a manufacturer and a retailer is taken as the research object. By considering the positive and negative effects from product energy efficiency level on product demand and recycling quantity, a differential game model is constructed to study the dynamic decision-making and coordination of closed-loop supply chain. Firstly, the dynamic evolution process of product energy efficiency level is described by differential equation, and then a differential game model is constructed under centralized and decentralized decision modes. Secondly, the optimal green innovation investment levels, promotional investment levels, product energy efficiency levels, recycling quantities and profits under two decision modes are given by applying the optimal control theory, and the comparative analyses are carried out. Thirdly, the bilateral cost sharing contract is proposed to coordinate the supply chain. Finally, the influences of key parameters on green innovation investment levels, product energy efficiency levels and channel profits are discussed by numerical examples, and the coordination effect of bilateral cost sharing contract is tested.
   The main conclusions obtained in this paper can be summarized as follows: The higher impact from product energy efficiency level on demand can effectively encourage manufacturers to invest more in green innovation, which leads to higher product energy efficiency level. In this case, although the return in the reverse channel will be adversely affected, the overall channel profit can still be increased. The increasing negative impact from the product energy efficiency level on the recycling quantity will enhance the green innovation investment of the product. When cost savings of remanufacturing increase, the manufacturers need to reduce the investment in green innovation to ensure better overall performance of the supply chain. Although the bilateral cost-sharing contract can obtain the same decision values as the centralized mode by restricting the behavior of supply chain members, it may not improve the benefits of the two channel members at the same time.
   The management implications of this paper are as follows: Firstly, in order to promote the high-quality development of closed-loop supply chain, both manufacturer and retailer should actively cooperate. Secondly, in the face of the adverse impact of the product energy efficiency level on the recycling quantity, enterprises should pay attention to improving the impact of the product energy efficiency level on the product market demand, otherwise there may be profit loss. Thirdly, it is not desirable to blindly carry out green innovation by increasing the innovation cost. When the impact of the product energy efficiency level on the recycling quantity becomes smaller or the unit cost savings of remanufacturing become larger, the manufacturer should appropriately reduce the green innovation investment to ensure the maximum benefit and the sustainability of green innovation. Finally, in practice, the bilateral cost-sharing contracts with transfer payments are more practical than traditional bilateral cost-sharing contracts.

Key words: green innovation, promotion, energy efficiency level, recycling quantity, bilateral cost-sharing contract