As an important engine for high-quality economic development, the digital economy is gradually integrating with the rural logistics industry. This trend is contributing to making rural logistics a fundamental, strategic, and pioneering industry. However, some valuable topics remain unstudied, such as whether they are coupled and whether there is variability in the coupling system across the provinces. Therefore, this article takes system theory and coupling theory as the analytical framework, aiming to better elaborate the subject’s logical relationship and operational structure of the coupled system, which is composed of a digital economy subsystem and a rural logistics subsystem. Furthermore, 21 provinces are seen as the research object in China, and the coupling coordination model is constructed, aiming to verify the coupling and coordination relationship between the two subsystems. The results suggest that two subsystems are coupled and coordinated in the same direction, and they feed back and influence each other. During the same period, four echelons are divided and there is variability in the coupling and coordination between the digital economy and rural logistics, according to the coupling degree (CD) and coupling coordination degree (CCD). Findings presented can serve as a useful reference for the evolutionary laws of the coupled system. The findings presented here can serve as a useful reference for the evolutionary laws of coupled systems. Moreover, it further provides ideas for the development between rural logistics and the digital economy.

Nowadays, in such a competitive business environment, under the pursuit of high quality and high standards, every enterprise has clearly realized that the quality of products is directly related to the interests of the enterprise, the development of the enterprise, and the survival of the enterprise. The idea that quality is life has long been deeply rooted in every enterprise. Based on the aforementioned reality, this paper first constructs a demand function affected by product quality, service quality, reference effect and quality competition, and studies the optimal product quality and service quality under centralized decision-making and decentralized decision-making. By comparing the decision values and profit difference between centralized decision making and decentralized decision making, a bilateral cost sharing contract is proposed, and its application scope is discussed. The major findings entail that the centralized decision-making mode of supply chain will be more conducive to improving service quality. However, it is not necessarily conducive to improving product quality, which depends on the marginal profits of competitors, since supply chain decision-makers are more willing to invest resources in products with high marginal profits, thereby improving product quality. The increase of reference effect is conducive to improving the quality of products and services, but it may also lead to higher production costs in the case of centralized decision-making. Therefore, when the reference effect is high, supply chain enterprises should adopt decentralized decision-making mode. Excessive competition is not conducive to improving the profits and increases internal friction among enterprises. Therefore, when the competition is fierce, enterprise alliance is a better choice. Finally, the bilateral cost sharing contract can coordinate the supply chain, that is to say, the system profit is equal to the profit of centralized decision-making. However, only when the supplier’s share rate meets certain conditions can the bilateral cost sharing contract achieve Pareto optimization, that is to say, when it is greater than the profit of the enterprise under decentralized decision-making.

Quality is not only the basis for business survival and development but also a key issue that cannot be ignored in supply chain management decisions. In practice, the impact of quality on goodwill does not show an immediate effect, and there is a dynamic delayed effect. Therefore, we developed a dynamic model that considers the delayed effect of quality on goodwill. Firstly, we constructed a delayed differential equation for the effect of quality on goodwill based on the Nerlove–Arrow model for a two-channel supply chain in a competitive environment and studied the dynamic quality decision problem of manufacturers and retailers under the delay effect. Secondly, we constructed the manufacturer and retailer Hamilton functions based on the principles of being of great value, solving and comparing the optimal product quality level, having an optimal service quality level, product goodwill, and overall profit of the supply chain under both decentralized and centralized decision modes, and investigated the effect of delay time on the profit and quality decisions of supply chain members. The conclusions show that: (i) delay time is an important reference for supply chain members when choosing the decision mode, and the overall profit size of the supply chain has different relationships with the different values of delay time taken into account with the two decision scenarios. (ii) Adopting a centralized decision mode can motivate manufacturers and retailers to improve the quality level, which in turn promotes the sales of products and the accumulation of brand goodwill.

The reference effect of consumers’ product quality and service quality is an important behavioral factor that affects consumers’ purchase decisions. In this paper, considering the inherent dynamics of the operation mode, the two were combined into a product-service supply chain composed of a manufacturer and two competitive retailers, and the service reference effect was further divided into horizontal and vertical service reference effects. Differential game models between the manufacturer and the retailers were constructed. Using the continuous dynamic programming theory, the manufacturer’s quality level strategy, retailer’s service level strategy and supply chain system performance under the modes of no cost sharing decision, cost sharing decision and centralized decision were analyzed and compared. Main findings: The optimal strategy of product quality under centralized decision is greater than the corresponding value under cost sharing contract decision. Compared with decentralized decision making of no cost sharing, cost sharing contract cannot promote the manufacturer to improve product quality. Different from previous studies, the service quality under centralized decision making is not higher than other decisions. When the horizontal reference effect of service quality meets a certain condition, the supply chain profit under centralized decision making is lower than the corresponding value under decentralized decision making.

Due to the sudden surge of orders, it is difficult for suppliers with a limited capacity to ensure that all orders are delivered in time and all the products are qualified. Suppliers are likely to put more limited capacity into completing orders, thus ignoring the quality of products. This will easily lead to the occurrence of product quality events, and then affect the goodwill of enterprise products. The innovations of this paper are as follows: first, based on the above facts, a negative and dynamic correlation between the delivery level and the quality level is established, which has been involved in previous studies. Second, the joint decision model of timely delivery, product quality, and marketing is constructed. Thirdly, centralized decision-making is the best way of supply chain cooperation, and cost sharing contracts can coordinate the supply chain. This paper provides guidance for enterprise managers when making decisions on quality, marketing and delivery. It also provides the basis for enterprise managers to formulate effective cooperation models. We can draw some research implications: when consumers are less sensitive to timely delivery, enterprises should give some coupons and small gifts to consumers in exchange for the extension of delivery time and put their limited capacity into improving the product quality. When consumers are highly sensitive to timely delivery, they can outsource some orders to cost-effective and professional third-party enterprises, which not only improves the delivery rate but also improves the product quality.