资金约束供应链的付款激励与协调研究

The research on motivating payment and coordinating the supply chain with capital constraints

面对由单个资金约束的制造商与单个资金约束的零售商组成的供应链,零售商存在三种付款方式,同时制造商提出提前付款时批发价折扣激励与延期付款的利率,本文从企业各自利润最大化出发,构建了不同付款方式下的供应链运营决策模型,并对比分散式供应链与集中式供应链的最优利润。研究表明:在不同付款方式下,资金约束的制造商与零售商均有动力进行外部融资且能够保证另一方参与供应链的运作。其次,零售商最优付款方式的选择主要是以批发价折扣率与融资服务利率为条件。再次,设计收益共享协调机制,不但部分改变了零售商最优付款方式的选择,而且能实现制造商和零售商利润的帕累托改进。最后通过算例分析验证了研究结论与所设计收益共享契约的有效性。

Capital is a fundamental resource in supply chains. Although noticeable literature assumes that capital constraints should not be considered. However, many microenterprises in China are short of funds, especially in start-up and fast-growing periods. One way to resolve this problem is for enterprises to borrow short-term loans from banks with fixed assets or sales receipts. Because of lack of full business information and trying to avoid financial risks, banks may afford a finite credit size. Thus, there will not be optimal decision-making in supply chains under limited working capital, which sharply influences an enterprise＇s profit. Another alternative way is trade credit, allowed by a manufacturer for a capital-constrained retailer, for delayed payment with an interest after delivering products. Moreover, trade credit refers to what a retailer pays to a capital-constrained manufacturer before receiving products. In addition to punctual payment, there are three main payment terms： advanced payment, punctual payment, and delay payment. However, many researches about capital-constrained supply chain mainly discussed the optimal decision-making under one payment term and analyzed how to choose the optimal financial channel to solve the limited capital for retailers. Few researches considered that both upstream and downstream supply chains do not have enough capital under different payment terms at the same time. Under the co-existence of stochastic demand and appropriate financial services from bank, a supply chain consists of one manufacturer and one retailer that have capital constraints. Without loss of generality, the initial capital of retailer or manufacturer is zero. The basic model is a classical single-period, make-to-order framework. Thus, the retailer prebooks quantity from manufacturer and sells it with an exogenously fixed price. The manufacturer has an incentive as wholesale price discount for advanced payment. However, if a retailer implements delayed payment, a manufacturer will announce per unit wholesale price with interest rate. In addition to the product market, there is also a financial market, such as banks. In order for the financial market to be competitive, the expected return of bank equates its loans with free risk rate. From the perspective of maximizing an enterprise＇s profit in supply chains, this paper constructs an operational decision-making model with different payment terms and compares the optimal profit of decentralized supply chain with centralized one. In the first part, we study the advanced payment scenario that retailer orders quantity and pays the money before production. Manufacturer then executes a wholesale price discount. We further discuss the punctual payment scenario which product sales and financial transactions take place simultaneously. The third scenario is to analyze the manufacturer announcing wholesale price with an interest rate in response to delayed payment. Using Stackelberg model and backward approach, we show the retailer＇s optimal preorder quantity and manufacturer＇s optimal discount rate or interest rate, and calculation formulas of optimal profit. In the second part, we further compare the retailer＇s optimal profit, and show that retailer will not choose delayed payment with different payment terms. In addition, we establish the conditions that retailer chooses the optimal single payment term based on wholesale price discount by manufacturer and interest rate given by bank. When the wholesale price discount and interest rate are lower, the retailer chooses advanced payment. When the wholesale price discount is lower and financing rate is higher, the retailer chooses punctual payment. When the wholesale price discount is higher, the retailer chooses advanced payment. We then compare optimal profit of a capital-constrained centralized supply chain with decentralized one, and show that besides an alternative operational strategy, a coordination contract, which is designed as revenue sharing, can not only partly change a retailer＇s choice of optimal payment terms, but also improve a manufacturer and a retailer＇s profit performance. Although the integrated supply chain＇s profit will be equal to the optimal profit of centralized supply chain under advanced payment or delayed payment scenario. Finally, a numerical example is used to verify the results and effectiveness of revenue sharing contracts. Our conclusions provide managerial insights into choosing optimal payment scheme and optimal incentive effect. In summary, although having limited working capital simultaneously, both retailer and manufacturer have nonnegative profit under different payments and ensure successful operations in supply chains. This paper only considers the optimal payment for retailers. Future research may to want to investigate optimal payment and asymmetrical information about manufacturing cost and multi-period operations.