【摘要】 时下，竞价排名的商品或服务已被显著标明“广告”，这种标记的有无将网购搜索排名区分为竞价排名与竞争排名，据此向消费者传递出不同信号，可能对消费者决策产生差异化影响。然而，现有研究尚未对此展开深入探索。本文基于信号理论，考察网购搜索排名的广告标记对消费者购买意向的影响。通过四个实验研究发现：较之有广告标记商品，消费者对无广告标记商品的购买意向更高；商品感知质量在上述关系中发挥中介作用；广告标记的直接影响与商品感知质量的中介效应在商品品牌强度较低或搜索排名靠前时显著，在商品品牌强度较高或搜索排名靠后时不显著。本文结论不仅丰富了竞价排名、信号关系和搜索排名位置的研究，而且对于商家优化平台营销策略具有重要启发意义。更多还原

【Abstract】 In recent years, e-commerce platforms represented by Alibaba, JD, eBay, and Amazon have emerged as major retail channels. In this context, most consumers rely on search engines offered by e-commerce platforms to identify their desired products. To maximize profits, however, platforms frequently auction top positions in search rankings to merchants with higher bids, a practice known as bidding ranking. Such bidding ranking has distorted fair competition in market transactions, weakened the matching accuracy of online product searches, and reduced overall transaction efficiency in e-commerce markets. As a result, it has drawn widespread criticism from both consumers and merchants and triggered regulatory concerns over the potential abuse of market dominance by e-commerce platforms. To tackle these problems, The Electronic Commerce Law of the People’s Republic of China explicitly mandates that e-commerce platforms shall display search results of products or services through multiple approaches based on price, sales volume, credit rating, and other relevant indicators; products or services promoted via bidding ranking must be conspicuously labeled “Advertisement”. In compliance with this legal requirement, leading platforms including Alibaba and JD have implemented such labeling for paid-ranked items. Nevertheless, the impact of such labels on consumers’ purchase intention remains under-explored in the existing literature.By distinguishing paid from organic search results, this mandatory labeling fundamentally changes how consumers interpret and respond to different ranking mechanisms. In practice, such labels categorize online search rankings into two types: bidding ranking(paid placement) and competitive ranking(organic ranking based on market performance), which convey distinct quality signals to consumers. Specifically, competitive ranking signals product quality based on real market feedback, whereas bidding ranking signals only merchants’ payment capacity rather than inherent product quality. These differences are thus expected to shape consumers’ perception of products or service quality and further exert a profound influence on their final purchase decisions. However, prior studies have mainly focused on the design of bidding ranking strategies from the perspectives of platforms and merchants, while largely overlooking consumers’ responses to advertising labels and the underlying psychological mechanisms. To address the research gap, this study, grounded in signaling theory, examines how advertising labels in online shopping search rankings inf luence consumers’ purchase intention, together with the mediating role of perceived quality and the moderating roles of brand strength and search ranking position.Four scenario-based experiments were conducted to test these hypotheses, with rigorous manipulation checks and reliability assessments to ensure the validity of these results. The main findings of this research can be summarized as follows. Consumers tend to exhibit a greater purchase intention towards products without advertising labels compared to those with advertising labels, and perceived quality plays a mediating role in this effect. The impact of advertising labels in online shopping search rankings on consumers’ purchase intention and the mediating effect of perceived product quality are significant when the brand strength of products is low, but they are no longer significant when the brand strength of products is high. Similarly, the impact and the mediating effect are significant when the search ranking is high, but not when the search ranking is low.The theoretical contributions of this study are threefold. First, it enriches the research on bidding ranking by shifting the focus from strategies of platforms and merchants to responses from consumers, providing empirical evidence for evaluating the regulatory effectiveness of mandatory advertising labeling stipulated in The Electronic Commerce Law of the People’s Republic of China. Second, grounded in signaling theory, this study distinguishes the differential signaling mechanisms between bidding ranking with advertising labels and competitive ranking without such labels, and reveals how advertising signals, market reputation signals, and brand signals interact to influence perceived quality and purchase intention, thereby extending the application and boundary of signaling theory in online shopping contexts. Third, it verifies the moderating roles of brand strength and search ranking position, clarifies when and why advertising labels produce significant effects, and reconciles inconsistent findings in prior studies regarding the value of ranking positions. By integrating the contingent effects of brand and ranking position, this study advances a more comprehensive understanding of search ranking mechanisms and consumer decision-making in e-commerce environments.With regard to practical application, the results of this study are able to provide substantial, practical and actionable managerial implications for online merchants engaged in platform operations, and concrete suggestions are further discussed in detail below. Merchants are advised to allocate more marketing resources to competitive ranking by improving the quality of products and services, which can better boost product visibility and effectively stimulate consumer purchases, especially for weak brands. On the other hand, merchants investing in bidding ranking should avoid blindly pursuing top positions and instead optimize their bids by balancing costs and marginal returns.更多还原