关键词: 绿色努力水平, 供应可靠性, 风险合同, 绿色供应链

Abstract: Existing studies mainly focus on the positive relationship between the manufacturer's green efforts and market demand under different decision-making backgrounds, but ignore the correlation between the supply reliability of products and the manufacturer's green effort. As a result, they may fail to consider its impact on the green supply chain operational decisions. Especially when considering the learning ability of the manufacturer, the level of green technology of the manufacturer is uncertain, which ultimately results in the supply risk of the manufacturer. Furthermore, the manufacturer still has a great decision-making concern about the level of green effort due to the huge cost that green investment may bring about. In view of this, this paper constructs a two-level supply chain consisting of a single retailer and a single manufacturer, in which the manufacturer is responsible for deciding the green effort level, and the follower retailer determines the optimal selling price. Considering the different green effort costs, this paper analyses the manufacturer's optimal green effort level under the exogenous and endogenous wholesale price, respectively. Furthermore, this paper measures impacts of risk-sharing contract and risk aversion contracts on operational performances of the green supply chain, respectively. The former indicates that regardless of the level of green effort put in by the manufacturer, the retailer should pay off the purchase cost of the products according to its order quantity; the former refers to the fact that the retailer pays off the purchase cost based on the manufacturer's expected final output. To sum up, this paper intends to systematically consider the following three research questions: (1)When supply reliability is positively related to the manufacturer's green effort level, how should the green supply chain optimize its effort level and operational strategy to maintain a balance between the economic and social benefits? (2)How do different risk contracts affect the manufacturer's green efforts and the operational performance of the supply chain? (3)How will the manufacturer and retailer adjust their operational strategies and improve their operational performance in the case of exogenous or endogenous wholesale price setting, respectively?
By formulating the manufacturer-dominated channel and defining the pressure coefficient of green effort level on supply chain, this paper accurately describes the optimal operational policies of the green supply chain. (1)Under exogenous wholesale price setting: (i)the risk-sharing contract enables the manufacturer to trade-off among three green effort strategies. Especially when the pressure coefficient is relatively higher, the manufacturer will choose the no green effort strategy; (ii)under the risk aversion contract, the manufacturer will keep the same green efforts since the retailer shares the part of the investment cost of green efforts; (iii)this paper accurately distinguishes the manufacturer's preferences towards different contracts. Especially when the pressure coefficient is rather larger, the manufacturer will be more inclined to the risk-averse contract. (2)Under the endogenous wholesale price, when the pressure coefficient is less than 1/8, the manufacturer will choose the risk-sharing contract, otherwise, the manufacturer will make contract selection based on the production cost. That is, when the production cost is relatively lower, the manufacturer will choose the risk-averse contract. Instead, the manufacturer will choose the risk-sharing contract. (3)In the long run, relying on the manufacturer to improve the green degree is a burden too heavy on the whole supply chain. Even if they can coordinate the competition and cooperation of the supply chain through contracts, the profits of the supply chain members will be greatly affected in many cases, and as a result, the members of the manufacturer will not even make green efforts. As the policy maker, the government can timely give some incentives to the supply chain, which may achieve better green results.
In view of this, the work of this paper can be further expanded from the following two dimensions. (1)Considering the importance and urgency of the two-carbon target, the government can further strengthen the green input level of the supply chain through a variety of mechanisms. For example, fiscal subsidies can be used to reduce enterprises' green costs and carbon emissions caused by production can be charged to restrict enterprises' operational strategy choices. (2)Considering manufacturers' green costs, the retailer can adjust its operational mechanisms to share the benefits, such as allowing the manufacturer to open direct channels, increase advertising investment to promote green product.

Key words: green effort level, supply reliability, risk contracts, green supply chain