关键词: 物流服务共享, 混合式电商平台, 竞争合作, 斯塔克伯格博弈

Abstract: With the rise of the platform economy, an increasing number of large B2C e-commerce enterprises have evolved into hybrid e-commerce platforms. These platforms not only provide consignment platforms for third-party sellers but also offer shared logistics services. However, such platforms are not always willing to share their logistics services. They might influence competition among channels by requiring sellers to offer differentiated products. Even in cases where platforms offer shared logistics services, sellers may not always opt for platform-provided logistics. The quality of these third-party logistics services significantly affects sellers' decisions regarding logistics. When both platforms and sellers make decisions regarding logistics services, they must balance the benefits and drawbacks of price competition and service competition. Two crucial factors that impact price and service competition are the degree of product substitution reflecting the intensity of competition among channels and the sensitivity of logistics services reflecting the impact of service competition.
This study considers a hybrid model e-commerce platform and a seller simultaneously utilizing the platform's reselling and consignment channels to sell products. The platform purchases goods from the seller at wholesale prices and resells them. It also charges the seller a certain commission to provide a consignment marketplace. The seller consigns substitute products of the same category through the platform. If a seller opts for third-party logistics, the seller needs to pay a fee to the third party for logistics services; otherwise, the seller pays a fee to the platform. The decisions of the platform and seller unfold in three stages: In the first stage, the platform decides whether to share its logistics services and determines the level of service and associated charges. In the second stage, the seller chooses a logistics service provider and sets wholesale prices and consignment channel selling prices. In the third stage, the platform determines reselling channel selling prices. The study assumes that the seller's choice of a logistics service provider is predetermined. Based on different choices regarding logistics service sharing between the platform and seller, a pricing and logistics service game model is established to determine the impact of logistics service strategies on the competition equilibrium between the platform and seller. Subsequently, by considering the influence of product substitution and logistics service sensitivity, the study analyzes the decision variables in two scenarios, exploring the impact of the platform and seller's shared logistics strategy on the competition equilibrium of logistics service levels and pricing. Finally, by considering the strategic interaction between the platform and seller, the study analyzes the equilibrium strategy choices of the platform and seller for different degrees of product substitution and logistics service sensitivity.
The research finds that when the seller chooses the platform's shared logistics, the platform will enhance its level of logistics services. It will only reduce the resale channel pricing when both the degree of product substitution and sensitivity to logistics services are relatively low; otherwise, it will increase the sales pricing. The platform is not always inclined to share its logistics services. When the degree of product substitution is low, the platform chooses not to share logistics services, and the seller opts for third-party logistics. When the degree of product substitution is high, regardless of whether the platform shares logistics services, the seller will choose third-party logistics, and in this scenario, the platform does not share its logistics services. Only when the degree of product substitution is moderate, the platform and the seller achieve Pareto improvement through the sharing of logistics services, and both choose the shared logistics services. Furthermore, when the level of third-party logistics services improves, the Pareto improvement region for the platform and seller shrinks, consequently, the platform tends to be less inclined to share its logistics services.

Key words: logistics service sharing, hybrid e-commerce platform, coopetition, Stackelberg game