Abstract: Based on a supply chain consisting of a manufacturer and an e-commerce platform, this paper examines the interaction mechanisms between manufacturer encroachment and platform demand information sharing in the context of demand-enhancing investments undertaken by the manufacturer. Based on whether the manufacturer pays a commission to the platform to open an agency channel and enter the platform (i.e., encroachment) and whether the platform shares demand information with the manufacturer, it develops four incomplete-information dynamic game models. The findings reveal that when investment efficiency is either high or low, manufacturer encroachment has no significant effect on platform information sharing. However, when investment efficiency is at a moderate level, sharing becomes complementary: manufacturer encroachment promotes platform information sharing, and platform information sharing further enhances the manufacturer’s incentive to encroach. When investment efficiency is moderately high, increasing the commission rate leads to the equilibrium strategy profile to transition along the path of “encroach+non sharing→encroach+sharing→non encroach+non sharing”. During this transition, the manufacturer’s (platform’s) profit exhibits upward (downward) jumps and shows a non-monotonic relationship with the commission rate. Additionally, when the commission rate is low and investment efficiency is high, encroachment increases the wholesale prices in the resale channel, a result that differs from previous literature.

Key words: demand information sharing, manufacturer encroachment, demand-enhancing investment, e-commerce platform, channel selection

摘要： 本研究基于由一个制造商与一个电商平台构成的供应链，在制造商通过投资活动提升市场需求的背景下，围绕“制造商是否向平台支付佣金以开通代理渠道进行入侵”与“平台是否向制造商分享需求信息”两个决策维度，构建了4个不完全信息动态博弈模型，以探讨需求改善投资下制造商渠道入侵与平台信息分享策略之间的交互机制。研究发现：当投资效率较高或较低时，制造商的渠道入侵行为对平台信息分享决策无显著影响；而当投资效率处于适中水平时，二者存在互补关系———即制造商入侵会促进平台信息分享，平台信息分享也会强化制造商的入侵动机。当投资效率处于中高水平时，随着佣金率上升，均衡策略组合将沿“入侵+不分享→入侵+分享→不入侵+不分享”的路径过渡。在策略组合变化过程中，制造商（平台）的利润会出现向上（下）跳跃，且二者均与佣金率呈非单调关系。此外，在佣金率较低且投资效率较高的情况下，渠道入侵会推高转售渠道批发价格，这一发现与以往研究结论有所不同。

关键词: 需求信息分享, 制造商入侵, 需求改善投资, 电商平台, 渠道选择