Abstract: In the context of economic globalization, as market competition intensifies, key parts suppliers may choose to produce terminal products by themselves, compete with manufacturers in downstream markets, and outsource cooperation with competitors at the same time. Samsung, for example, sells its phones in the consumer market in addition to supplying premium screens to competitors like Apple and Xiaomi. In this context, suppliers producing key parts may face the choice of competing with product manufacturers in downstream markets due to their technological advantages, encroaching on the retail market or focusing on providing outsourcing services for key parts to manufacturers. At the same time, the manufacturer can choose to bear the cost of producing the parts themselves or outsource them to a cost advantage supplier. But the availability of such a critical component could trigger changes in the companies' consumer base. When the manufacturer chooses to outsource, more consumers will be aware of the existence of the supplier, and thus may be aware of the supplier's products. This phenomenon, which is caused by cooperation, promotion and other factors, is known as the spillover effect of consumer awareness. For example, when Xiaomi, Huawei and other mobile phone manufacturers release mobile phones, they will emphasize the quality screen provided by Samsung. Some users who do not know Samsung may realize the existence of Samsung mobile phones from the publicity or distinctive logos, and choose to buy its mobile phones. This is because the spillover effect of consumer awareness enriches customers' purchase choices and intensifies market competition, thus affecting the strategic choices of parts outsourcing and market encroachment. Although many scholars have studied the spillover effect of consumer awareness in various aspects, the demand spillover resulting from outsourcing has not been investigated. In addition, most of the above literatures only consider the outsourcing selection of one party. Therefore, the study of how the spillover effect of consumer awareness affects suppliers' market encroachment and manufacturers' outsourcing decisions can contribute to enriching supply chain outsourcing literature and providing theoretical basis for supply chain management and practice.
In view of the competition and cooperation structure of the supply chain mentioned above and the fact that the existing outsourcing literature does not consider the spillover effect of consumer awareness, this paper explores in depth how the spillover effect of consumer awareness affects the market encroachment of suppliers and the outsourcing decision of manufacturers. Considering the spillover effect of consumer awareness and cost advantage, we construct a two-level supply chain game theory model consisting of one supplier and one manufacturer, and obtain the results of sub-game equilibrium in four cases of supplier's market encroachment and the outsourcing decision of the supply chain by the backward induction. The impacts of the spillover effect and cost on the equilibrium results are further analyzed. Finally, we resort to numerical analyses to explore the supplier's encroachment strategy and profit changes with respect to the cost.
The research shows that, due to the behavior of suppliers inducing manufacturers to outsource, the spillover effect of consumer awareness has two sides. The party in the supply chain that tends to choose outsourcing suffers the negative impact of spillover effect. When the manufacturer is motivated to choose outsourcing, the larger the spillover effect is, the more beneficial it is to the supplier, and vice versa. The spillover effect of consumer awareness also reduces the incentives of both manufacturers and suppliers to outsource. In addition, when the supplier encroaches on the market, inducing the manufacturer to outsource needs to provide a wholesale price lower than the cost. Under the composite influence of double marginalization effect and efficiency improvement effect, when the manufacturer's cost is low, the supply chain profit will rise with an increase in the cost. When the intrusion strategy of suppliers is considered and the spillover effect of consumers is large, the manufacturer may obtain higher profits at a moderate cost than those at a low cost due to the moderating market competition, and the profit of the supply chain will be improved.

Key words: spillover effects, consumer awareness, market encroachment, dynamic game, outsourcing

摘要： 随着市场竞争加剧,供应链上游供应商可能会选择在下游市场与制造商竞争。当供应商为制造商提供关键零部件时,部分了解制造商产品的消费者会意识到供应商的存在,从而关注到供应商的产品。基于上述消费者意识溢出效应,构建一个考虑供应商可能产品入侵的制造商部件外包决策模型,分析供应商入侵与不入侵市场时的博弈均衡结果,最后通过数值仿真进一步研究供应商入侵市场的策略选择。研究发现消费者意识溢出效应存在两面性,当制造商有动机选择外包时,溢出效应越大越有利供应商,反之则有利于制造商,消费者意识溢出效应同时减少了制造商和供应商双方选择外包的动机。另外,当供应商入侵市场时,诱导制造商外包需要提供低于成本的批发价;受双重边际效应和效率提升效应共同影响,供应链利润可能随着制造商成本的上升而增加。

关键词: 溢出效应, 消费者意识, 市场侵占, 动态博弈, 外包