There is a two-tier supply chain consisting of a strong manufacturer and a weak retailer where the manufacturer dominates and is the leader. The retailers are risk neutral and fair neutral, while the manufacturer can be divided into the three types according to different behavioral preferences: risk neutral and fair neutral, risk averse and fair neutral, and risk averse and fair concerned.
These parameters are set as follows. According to the market and previous literature, for example, represents the uncertain market size and its mean is . The variance is and satisfies . The price elasticity coefficient of market demand is . The sensitivity coefficient of consumers to product greenness is and satisfies . The price of the retailer’s unit product is and the demand function is . To simplify the model operation, the problem of the overcapacity or insufficient capacity of the manufacturer is not considered in the research, where the market sales volume is , . The manufacturer’s unit production cost is and the wholesale price is . The subscripts and represent the retailer and the manufacturer, respectively.
In order to describe the model and fit the reality better, this research has the following assumptions: First, the investment cost of green technology is
, and according to the background of the text, the manufacturer fully bears the technical cost, whereby
is the green investment coefficient. Second, consumers, in response to the call of the state and because of their own preferences, tend to choose low-carbon products or green products, where
represents the consumer green sensitivity coefficient and
represents the product green degree. According to previous literature, both parameters are greater than 0. Third, to operate normally, the parameters such as production cost and retail price should satisfy
. Fourth, the average market size is a value greater than the cost
. Fifth, the superscripts 1, 2, and 3 indicate that the manufacturer is a risk-neutral and fair-neutral decision maker, a risk-aversion and fair-neutral decision maker, and a risk-aversion and fairness-concern decision maker, respectively. Some of the parameters have been listed as follows in
Table 2.
2.1. The Risk-Neutral and Fair-Neutral Manufacturer
According to assumptions, the Stackelberg game is more in line with the actual market situation. According to the process of supply chain events, based on the actual situation, the manufacturer first produces the product at the unit cost
as the leader of the supply chain. To meet the market demand and the low-carbon preference of consumers, the wholesale price of the product can be determined as
, and the product green level is
. Then, the retailer orders
products according to the manufacturer’s wholesale price to set the product retail price
in the market. The model can be solved using the inverse method (
Appendix A):
Proposition 1. When the manufacturer and retailer have no risk-averse behavior, both are risk neutral, and the optimal decision and optimal profit of the supply chain members are as follows:
Theorem 1. According to proposition 1, the manufacturer’s optimal decision
increases with the consumer green sensitivity coefficient
. So, the manufacturer’s optimal profit also increases with the sensitivity coefficient
. When the manufacturer makes the optimal decision, the retailer makes the optimal decision
, increasing with
.
Theorem 1 shows that in the case of the unchanged market environment, the risk-neutral manufacturer will tend to be ‘risky’ at this time. To ensure the growth of the market share, as consumers pay attention to product emission reduction and green level, the manufacturer takes the initiative to increase investment in green products and increase the wholesale price. As consumer demand increases, retailers increase the retail price in order to increase profits and offset some of the increased costs. Finally, the green product market enters a virtuous circle.
2.2. The Risk-Averse and Fair-Neutral Manufacturer
When the manufacturer has risk aversion behavior, the ‘mean-variance method’ is used to set the manufacturer’s expected profit function as:
where
represents the manufacturer’s risk aversion coefficient
, and the manufacturer’s risk aversion varies with the value of
. Similar to the above, the model is described as:
Proposition 2. When the manufacturer is risk averse and the retailer is risk neutral, where both are fair neutral, the optimal decision and optimal profit of the supply chain members are as follows:
Theorem 2.
Proposition 2 shows that the manufacturer’s optimal decision decreases with the risk aversion coefficient
, and the manufacturer’s optimal profit also decreases with the risk aversion coefficient
. When the manufacturer makes decisions, according to the known situation, the retailer’s optimal decision
decreases with the risk aversion coefficient
, and the retailer’s optimal profit increases with
.
Theorem 2 shows that in the case of a constant market environment, because of risk aversion, the manufacturer tends to be ‘conservative’ to ensure long-term cooperation with retailers. With the deepening of risk aversion, the manufacturer takes the initiative to reduce the wholesale price. The retailer tends to lower retail prices to ensure an increase in market share but achieves a ‘small profit and quick return’ effect. For consumers, the manufacturer’s risk aversion provokes them to buy more green or low-carbon products.
2.3. The Risk-Averse and Fairness-Concerned Manufacturer
According to the process of supply chain events, unlike
Section 2.1, the manufacturer first produces the product at unit cost
. The manufacturer predicts the retailer’s optimal decision in advance because of its own preferences, and then the wholesale price of the product can be determined as
. The retailer orders
products according to the manufacturer’s wholesale price to set the product retail price
for sale in the market.
When the manufacturer has fairness concerns, it can be divided into the following two situations: if the manufacturer perceives that its profit is lower than the retailer’s, it will suffer additional negative utility due to jealousy, which is called the negative utility caused by disadvantageous unfairness. On the contrary, if their own utility is higher than that of the retailers, they will suffer from the negative utility of sympathy, which is called the negative utility caused by advantageous fairness. At this point, the manufacturer’s expected profit function can be described as follows, according to Cui et al. [
39]:
where
where
is the manufacturer’s disadvantageous fairness concern coefficient and
is the manufacturer’s advantageous fairness concern coefficient. The hypothesis is satisfied:
.
Proposition 3. When the retailer is risk neutral and fair neutral, the manufacturer is affected by risk aversion under the manufacturer’s fairness concern. Different from the previous literature (the manufacturer’s profit is greater than the retailer’s profit), the manufacturer is more disadvantageous than the retailer and has smaller profit because of a high degree of risk aversion.
Proposition 3 shows that under an unchanged market environment, the manufacturer will tend to be ‘conservative’ and ‘overcautious’ because of the dual impact of risk aversion and fairness concerns. As the degree of risk aversion deepens, the manufacturer actively reduces the wholesale price. But at the same time, the manufacturer pays attention to the retailer’s profits and will reduce the number of green products. Disadvantageous fairness concerns have caused manufacturers to suffer losses. For green industries, enterprises should take more care of the effectiveness of competitors or partners.
Similar to the above, the following game model is solved by inverse induction:
(I). If
, the manufacturer has advantageous fairness concerns. Therefore, the optimization problem is as follows:
The optimal decision and profit of the manufacturer and the retailer are calculated and simplified as:
where
Theorem 3. When
, the manufacturer’s optimal decision
decreases with the risk aversion coefficient
, and the manufacturer’s green investment decreases with the increase in the risk aversion’s degree. When the manufacturer makes the optimal decision, the retailer’s optimal decision
decreases with
according to the known situation.
Theorem 3 shows that under an unchanged market environment, the manufacturer will be more ‘conservative’ and pay attention to the retailer’s lower profits because of the influence of risk aversion and advantageous fairness concern. The manufacturer not only ensures long-term cooperation with the retailer but also suffers from the ‘guilt’ caused by the advantageous fairness concern. With the deepening of risk aversion, the leader prefers to reduce the wholesale price to increase the retailer’s profit; because of the market demand’s uncertainty, the manufacturer’s expected demand is inconsistent with the actual demand, causing a decline in investments in green products. Retailers will lower retail prices for ‘small profit and quick return’ purposes.
Theorem 4. When and the market size is larger, after the manufacturer’s optimal decision, the optimal utility
decreases with the risk aversion coefficient
. After the retailer’s decision based on the known information, the optimal profit
increases with the risk aversion coefficient
.
Theorem 4 shows that in the market, the manufacturer is affected by risk aversion and chooses to reduce control over market forces. Therefore, the manufacturer will obtain less profit. And the retailer will obtain more market power to benefit more from the sales.
Proposition 4. When
, the manufacturer’s optimal decision decreases with the fairness concern coefficient , and the manufacturer’s green investment increases with the increase in the advantageous fairness concern coefficient. When the manufacturer makes the optimal decision, the retailer’s optimal decision decreases with the fairness concern coefficient .
Proposition 4 shows that in the case of the unchanged market environment, the manufacturer will be affected by the ‘guilt’ brought on by the advantageous fairness concern. Then, the manufacturer tends to transfer some profits to the retailer. The manufacturer makes the product more attractive for consumers and increases green technology investments. Therefore, the product green degree increases, so the retailer will acquire more orders. With the deepening of fairness concerns, manufacturers reduce the wholesale price, and retailers will reduce prices to achieve more sales and profit.
Theorem 5. When the market size is larger, the fairness concern coefficient satisfies After the retailer’s decision based on the known market information, the optimal profit decreases with the fairness concern coefficient . Otherwise, the retailer’s optimal profit increases with .
Theorem 6. When the market size is larger, and
satisfy
or
, and the optimal utility
decreases with the fair concern coefficient
. Otherwise, increases with the fairness concern coefficient
.
Theorems 5 and 6 show that under the unchanged market environment, the manufacturer will be affected by ‘guilt’ because of the advantageous fairness concerns. Although the market size becomes smaller, the cost of the retailer is reduced to increase its profit. However, if the manufacturer’s unfair feelings are obvious, the retailer’s order quantity becomes larger. Under the action of two factors, the manufacturer still has the first-mover advantage, and the manufacturer’s profit increases.
(II) If
, the manufacturer has disadvantageous fairness concerns. Therefore, the optimization problem is as follows:
The optimal decision and profit of the manufacturer and the retailer are calculated and simplified as:
where
In case II, from the analysis, the manufacturer’s disadvantageous fairness concern is caused by its own low utility. When the disadvantageous fairness concern coefficient is large, it indicates that the manufacturer is no longer in the dominant position in the supply chain. The profit is quite different than expected, causing the manufacturer to reduce the green technology investment; as a result, the reduction in the product green level results in the increase in the wholesale price. Even the cooperation relationship between supply chain members will break down, and this is also because the retailer does not have fairness concerns. For them, the impact of deepening their disadvantageous fairness concerns will not only increase the wholesale price but also reduce the green degree of products. The manufacturer is no longer in a dominant position in the supply chain, violating the research hypothesis. Therefore, the specific decisions of members in the supply chain are not considered in the research.