Should traditional retailers function as pre-warehouses of online retailers?

We construct a supply chain to investigate the reason why it is uncommon for the traditional retailer to function as the pre-warehouse of the online retailer. The product only offered by the traditional retailer is labelled as the differentiated product, while the product supplied by both the traditional retailer and the third-party suppliers is called the common product. As the online retailer' common product competes directly with the differentiated product, whether the traditional retailer should supply the common product becomes sophisticated. In this paper, we identify an intrinsic rationale for the traditional retailer not to supply the common product, even if he is unambiguously cost advantageous vis-a-vis the third-party suppliers. This is because the online retailer's order serves as a commitment device that puts the traditional retailer at the disadvantageous follower's position in the differentiated and common products competition; moreover, this quantity commitment allows the online retailer to clinch a better bargaining position on the differentiated product. We further show that it never pays the online retailer to split orders between the traditional retailer and the third-party suppliers. Our results are robust against the traditional retailer's capacity constraint, consumers' preference over differentiated and common products, and supply chain contractual form.本文构建一条供应链，以探究传统零售商鲜有充任在线零售商前置仓库的缘由。仅由传统零售商供应的产品被定义为差异化产品（differentiated product），而由传统零售商与第三方供应商共同供应的产品则被称为共同产品（common product）。由于在线零售商的共同产品会与差异化产品形成直接竞争，传统零售商是否应当供应共同产品便成为一个复杂的问题。本文揭示了即便传统零售商相较于第三方供应商具备明确的成本优势，其仍不愿供应共同产品的内在逻辑。这是由于在线零售商的订单构成了一种承诺机制，使得传统零售商在差异化产品与共同产品的竞争中处于不利的跟随者位置；此外，这种产量承诺能够让在线零售商在差异化产品的谈判中获得更优的议价地位。本文进一步证明，在线零售商将订单拆分给传统零售商与第三方供应商的做法毫无收益可言。本文结论在传统零售商产能约束、消费者对差异化产品与共同产品的偏好，以及供应链契约形式等场景下均具有稳健性。