Abstract: With the intensification of competition and changes in the market environment, many e-commerce platforms, such as Amazon and JD.com, have gradually switched from the pure mode of distributing manufacturers' products (i.e., reselling mode) or providing a marketplace to sellers (i.e., agency selling mode) to a hybrid mode.The platform not only provides marketplaces for retailers to connect with consumers, but also acts as e-retailers to distribute manufacturers' products. Meanwhile, some supply chain enterprises are facing the severe situation of withdrawing from the market or being merged with the increasingly fierce competition. Firms gradually realize the importance of alliance. In some fields or markets, long-term and stable profits can be obtained by allying with other supply chain members. For example, P&G allied with Walmart and reduced the operating cost of the whole supply chain. Midea and Gree reached a strategic alliance with JD. However, an improper choice of the alliance strategy will also harm the profits of both members and eventually lead to the rupture of the alliance relationship. For example, Nike Group terminated its alliance with the online retailer Zappos. Therefore, it is of great significance to characterize the manufacturer's alliance strategy in an online retailing supply chain.
In this paper, we construct an online retailing co-opetitive supply chain consisting of one manufacturer, one retailer, and one platform. The manufacturer sells products to the retailer and platform at wholesale prices. The retailer opens a franchise store to sell products on the marketplace of the platform by paying a commission fee. The platform not only provides a marketplace to the retailer, but also builds a self-operated flagship store to resell the manufacturer's products. Hence, the revenue of the platform comes from the commission fee paid by the retailer and the profit from reselling products. It is worth noting that, on the one hand, the retailer and platform distribute the manufacturer's products and compete horizontally in the terminal market. On the other hand, the retailer sells products on the marketplace by paying a commission fee and cooperates vertically with the platform. Thus, there is a co-opetitive relationship between the retailer and platform. In this online retailing co-opetitive supply chain, the manufacturer has three alliance models: having no alliance, allying with the retailer, and allying with the platform. Considering the differences in sales entities and channels, the retailer and platform have different initial market demands. Based on the above analysis, this paper examines the impact of different initial market demands on the manufacturer's alliance strategy choice in an online co-opetitive supply chain.
The main research is arranged as follows: Firstly, we take the no alliance model as a benchmark to explore whether the manufacturer has an incentive to ally with the retailer or platform, and analyze the impact of the alliance on the third-party member's profit. Secondly, we compare and analyze which member the manufacturer is more inclined to ally with. Then, we study the influence of different alliance strategies on the whole supply chain profits, social welfare, and consumer surplus. Finally, we relax the assumptions and expand the discussion on the manufacturer's alliance strategy choice in two situations, i.e., quantity competition, and the platform as the channel leader.
The results show that: (1)The manufacturer always has incentives to ally with the retailer or platform. However, which member the manufacturer is more motivated to ally with is related to the platform's commission rate and the initial market demand ratio of different channels. Specifically, when the commission rate is low and the initial market demand ratio is large, the manufacturer is more inclined to ally with the retailer; otherwise, he prefers to ally with the platform. (2)The profit of the platform (retailer) will not always decrease when the manufacturer allies with the retailer (platform). Specifically, when the commission rate is within the appropriate range, the platform (retailer) will benefit from the alliance between the manufacturer and retailer (platform) if the initial market demand ratio is large. (3)When the initial market demand ratio is small, the manufacturer allying with the platform can achieve a win-win-win situation for the whole supply chain, consumer surplus, and social welfare. When the initial market demand ratio is large, the manufacturer allying with the retailer can achieve a win-win-win situation.

Key words: online retailing supply chain, alliance strategy, asymmetric initial market demands

摘要： 在由制造商、零售商和平台商组成的线上零售供应链中,考虑下游零售商和平台商之间既竞争又合作的竞合关系,研究了渠道初始市场需求不对称对制造商合作策略选择的影响。运用博弈方法从制造商的视角分别构建了不合作、与零售商合作、与平台商合作三种策略模型。在此基础上,首先,以不合作模型为基准,分析了制造商是否有动机与下游成员合作;然后,比较了不同策略下的合作动机大小问题。研究结果表明:制造商与零售商、平台商均有合作的动机。然而,其合作动机大小与佣金费率以及渠道初始市场需求比率有关。当佣金费率较低且初始市场需求比率较大时,制造商更倾向与零售商合作;否则,其与平台商合作动机更大。有趣的是,制造商与零售商(平台商)合作并非总是损害平台商(零售商)的利润。当佣金费率满足一定条件时,若初始市场需求比率较大,则平台商(零售商)可以从制造商与零售商(平台商)的合作中获益。最后,讨论了数量竞争和平台商为领导者两种情形下制造商的合作策略选择。

关键词: 线上竞合供应链, 合作策略, 不同初始市场需求