Abstract: In the past decade, e-commerce platforms have witnessed a strong growth in online sales. Some manufacturers establish online channels through retailers, such as ERKE, Walmart, Nike China, etc. However, opening an offline direct store has become an important part of the future development for some manufacturers. Significantly, manufacturers encroaching the market through offline channels have also impacted online channels and damaged online retailers' profits. Currently, coupon promotions have become an important means for online retailers to increase sales, and in the context of encroachment, placing coupon may become an effective means for retailers to prevent or suppress the manufacturers' encroachment. In practice, the offline channel operation efficiency of manufacturers is their private information, and it is not held by retailers. Asymmetric channel operation efficiency provides more space for manufacturers to encroach the market through offline channel, but is not conducive to retailers' ordering decisions. Based on this, the following questions need to be addressed: Firstly, does the manufacturer with private information have the motivation to share channel operation efficiency information with the retailer? If so, how to convey information? Secondly, is coupon always beneficial for the retailer, and how do coupon strategies affect manufacturer's channel strategies? Thirdly, are the effects of information asymmetry and coupon on the decisions of the manufacturer and retailer consistent? The research on the above issues provides theoretical methods for the formulation of market strategies between e-commerce enterprises and manufacturers under e-commerce discounts and information asymmetry, and is also conducive to efficient operation of the supply chain and orderly competition among channel members.
Based on the signal game theory and business practice, this paper mainly analyzes the information sharing mechanism under encroachment and coupon. Embedding coupon into manufacturer's channel operation and utilizing the impact of online coupon on demand, this paper explores whether coupon can help retailers resist the manufacturers' offline encroachment behavior. Secondly, based on the optimization of supply chain operations, this paper provides strategic choices and consensus among the e-commerce platform, retailer, and manufacturer. The results show that the manufacturer's encroachment behavior changes the supply chain information structure, leading to different pricing strategies for high and low type manufacturers. Under information asymmetry, the information mechanism of the manufacturer is influenced by differences in channel operation efficiency and retailer's initial belief. When differences in channel operation efficiency are small, the manufacturer prefers not to share information, and vice versa. Asymmetric information reduces the wholesale price and profits for the high type manufacturer, while increasing profits for the retailer, e-commerce platform, and supply chain. Coupon from e-commerce platform expands the asymmetric information effect and increases the difficulty of information sharing for the manufacturer. However, it does not change the information mechanism of the manufacturer. Under certain conditions, retailer can suppress the manufacturer's encroachment through offering coupon.
Based on the findings of this article, the following management insights can be obtained: e-commerce platforms and retailers should not blindly offer coupon when pursuing a higher performance. Before decision, it is necessary to fully understand changes in consumer perception in the market and make business decisions based on the relevant information. The relationship between the e-commerce platform and retailer is not solely based on profit sharing. In fact, the retailer can leverage the advantages of e-commerce platforms in coupon to suppress the manufacturer's encroachment behavior and achieve a win-win situation. Secondly, an information advantage is not necessarily a good thing for supply chain members, as information asymmetry may cause unnecessary losses. It is imperative to establish a reliable, transparent, and low-cost information sharing mechanism beforehand.
Although this paper focuses on the commercial behavior of e-commerce platforms in coupon, it ignores the situation where the retailer offers coupon. Therefore, exploring the impact of retailer's coupon behavior on the manufacturer's encroachment will be an interesting topic for further research.

Key words: channel efficiency, asymmetric information, coupon, information sharing

摘要： 本文在渠道运作效率非对称下建立了一个由零售商、电商平台和制造商构成的供应链模型,研究了信息非对称下线上优惠券投放对制造商的信息分享机制及制造商线下渠道运作的影响。研究表明:无优惠券投放下,制造商入侵引发的信息非对称降低了高类型制造商的收益,但提高了零售商、电商平台及供应链的收益;制造商并不总是偏好与零售商共享信息,仅当渠道运作差异较小时,制造商偏好不共享信息;线上优惠券投放扩大了信息非对称效应,拉低了制造商的批发价格,加剧了制造商信息共享的难度。此外,优惠券敏感系数和渠道效率差异满足一定条件时,零售商可以通过优惠券策略抑制制造商线下渠道入侵。

关键词: 渠道效率, 信息非对称, 优惠券, 信息共享