平台经济的可竞争性——用户注意力的视角

The Contestability of the Platform Economy:A User Attention Perspective

既有文献基于交叉网络效应认为平台经济容易形成高度的垄断,无法解释平台企业激烈竞争的特征性事实。本文通过引入用户注意力因素,提出交叉网络效应的作用基础是用户流量,而非用户数量,并分析用户注意力分配对平台企业市场竞争的作用机制。在基于用户流量的交叉网络效应的作用下,平台经济尽管呈现出规模效应,但仍然是高度可竞争性经济。当用户规模给定时,随着注意力网络效应的增加,平台之间的竞争加剧,平台企业最优定价和利润水平不断趋向于完全竞争的情形。而当用户规模可以快速增加时,则竞争程度会下降。这些发现能够很好地解释平台经济规模收益和竞争性并存的特征性事实,为完善平台经济治理体系,平衡行政监管和市场竞争,提供更为科学的理论基础。

Traditional bilateral market literature characterizes the non-competitiveness of platform economies arising from cross-group network externalities based on user quantity.Although some scholars believe that the non-competitiveness of platforms does not harm user welfare and market efficiency,many scholars and government departments tend to believe that platform monopolies produce undesirable outcomes,prompting calls for antitrust regulation of platform companies.This paper argues that understanding the competitiveness of the platform economy requires consideration of user attention factors,and the essential of cross-group network effects should be user traffic that includes attention factors,rather than user quantity.User traffic refers to all user attention attracted by a platform company,represented by the product of average visit duration and user quantity.Given two platforms with similar user scales,differences in average visit duration will result in significant disparities in user traffic resources,and hence,in the platforms'attractiveness to merchants.Thus,attention and user traffic are the essentials of cross-group network effects.Due to the finite nature of consumers'attention resources,which are allocated across various platforms,competition arises not only between similar platforms,but also between different types of platforms,leading to cross-boundary competition.Therefore,understanding the competitiveness of the platform economy requires examining the competitive process and mechanisms by which different types of platform companies vie for user attention from the perspective of the attention market.This paper identifies four key facts about platform competition in the real economy:rising customer acquisition costs,advertising revenues exceeding matchmaking revenues,increasingly intense cross-boundary competition,and growing dynamic competition between platforms.Based on these empirical observations,this paper proposes the contestability theory of the platform economy,which is an extension and development of Baumol's contestability theory.The contestability of the platform economy implies that despite high market concentration,the platform economy remains competitive,encompassing both cross-boundary competition between differentiated platform companies and dynamic competition between new and established platforms,preventing the formation of a stable monopolistic industry structure.To elucidate the contestability theory of the platform economy,this paper adopts a market structure perspective based on attention,introduces the Dixit-Stiglitz aggregator utility function to describe the equilibrium distribution of consumers'attention across different types of platforms,and analyzes its impact on platform competition.Moreover,to emphasize the impact of user traffic rather than user quantity on cross-group network effects,the paper distinguishes between exogenous and endogenous user scale scenarios.The former,our baseline model,primarily examines the mechanisms by which user attention allocation affects market competition among differentiated platform companies;the latter,an extended model,comprehensively analyzes the mechanisms and key parameter effects determining optimal pricing behaviors and equilibrium profit levels for platform companies in terms of both user quantity and attention allocation(i.e.,user traffic),supported by numerical simulation analysis.Our main findings are as follows.(1)When user scale is exogenously given,competition intensifies as attention network effects increase,with the vertical(core)business market gradually converging toward perfect competition.Optimal pricing and profit levels of platform companies'core businesses decrease with the enhancement of attention network effects and platform substitutability,and profits and platform quantity are inversely related.(2)When user scale is endogenous and rapidly increasing,the degree of competition decreases,and equilibrium profits are positively correlated with attention network effects,platform substitutability,and platform quantity.These findings provide valuable insights into the coexistence of scale benefits and competitiveness in the platform economy and offer a more robust theoretical foundation for refining governance systems for the platform economy and balancing administrative oversight and market competition.Based on these findings,this paper's main policy recommendation is that considering China's saturated Internet traffic resources and intensified traffic competition of the platform economy,platform companies'monopoly positions will decline under market competition pressure.Therefore,governance and regulation of the platform economy should focus more on the development and rational utilization of traffic resources,encouraging platform companies to adopt ecosystem strategies and“go global”strategies to promote the healthy and sustained development of the platform economy.