| With the vigorous development of the platform economy,prominent problems such as abuse of dominance by digital platforms,exclusion and restriction of competition have emerged around the world(Sun Jin,2020).How to build a platform economic governance system and effectively supervise the behavior of digital platforms has become a very challenging issue faced by government regulators around the world.Since the meeting of the Political Bureau of the Central Committee in December 2020 put forward “anti-monopoly and prevention of disorderly expansion of capital” for the first time,the domestic anti-monopoly deployment has been fully rolled out,and the digital platform economy is the first to bear the brunt of anti-monopoly supervision.A three-dimensional supervision system in the economic field of digital platforms has been built quickly,and antimonopoly law enforcement against platform companies’ “choose one” exclusive monopoly agreements and platform mergers and acquisitions operator concentration and other overt monopoly behaviors has been vigorously carried out.With the indepth advancement of anti-monopoly enforcement,the use of algorithms as a means to implement an implicit conspiracy monopoly in the digital platform field brings technical difficulties in regulatory identification,identification and regulation.With the development of the platform economy entering a mature stage,the platform market tends to be saturated,the scale and territory are gradually stabilized,and the competitive strategy of platform companies has also shifted from "staking" to "collective price increase",and the hidden collusion risk in the platform market has become more and more prominent.In this context,the research of this paper starts from the perspective of economics,aiming at the secrecy of the algorithm collusion of platform enterprises,applying non-cooperative game theory to analyze the tacit collusion motivation and collusion mechanism of platform enterprises,and revealing the unique network externalities of the digital platform market.The role of sexual characteristics in the collusion motivation and collusion mechanism of platform enterprises.By constructing an indefinite repeated game model of duopoly platform enterprises,this paper examines the tacit collusion motivation,collusion equilibrium and collusion stability of platform enterprises in three basic platform market structures—horizontal difference platform market,vertical difference platform market and bilateral platform market.It is influenced by factors such as intra-group network effect,degree of product differentiation,and between-group network effect.First of all,this paper takes the shared bicycle platform market as an example to analyze the motive,mechanism and stability of the collusion of duopoly platform enterprises in the unilateral platform market with horizontal differentiation under the network effect,and examines the influence of the network effect on the collusion among bicycle platform enterprises.The influence of stability,and the influence of the degree of horizontal differentiation on the stability of enterprise collusion under the network effect is re-considered,and compared with the classical research conclusions under the non-network effect.This paper finds that the network effect has an inhibitory effect on the collusion between enterprises on the shared bicycle platform.The stronger the network effect,the more unstable the collusion between enterprises.Under the network effect,the impact of the expansion of the degree of horizontal differentiation between the shared bicycle platforms on the stability of collusion is not monotonous,but depends on the strength of the network effect,especially when the network effect is strong,as the horizontal differentiation expands,Collusion among platform firms becomes more volatile,contrary to the classic conclusion of traditional product markets without network effects(Deneckere,1983).When network effects are strong,collusion under price competition is more stable than that under output competition,which is also the opposite of the conclusion when network effects are not considered(Deneckere,1983).Secondly,this paper takes the online car-hailing platform market as an example to further analyze the collusion between platform companies in addition to horizontal differentiation and vertical differentiation.For online car-hailing services,on the premise that they can meet the needs of safe travel,from the perspective of consumer travel efficiency,when a(class)online car-hailing platform can provide faster taxi services,it can It is believed that the online car-hailing platform can provide higher quality services.The research in this chapter takes into account the characteristics of horizontal differentiation among platform companies while discussing vertical differentiation.Therefore,this chapter is based on the adjustment of Hotelling by Griva(2011),according to the characteristics of the platform market,introduces and simplifies network effects and quality parameters,analyzes In a vertically differentiated car-hailing platform market,network effects and the influence of collusion motivation and collusion stability on oligopolistic enterprises of different qualities.This paper finds that network effects will inhibit the stability of low-quality online car-hailing platforms participating in collusion,while the impact on high-quality platform companies participating in collusion is not monotonous,but is related to the degree of quality difference between platform companies.The stronger the network effect,the higher the stability of high-quality platform companies’ participation in collusion;the expansion of vertical market differentiation will be detrimental to the stability of low-quality platform companies’ participation in collusion,while for high-quality platform companies,the impact is not monotonous,but depends on network effects.Among them,when the network effect is strong,the expansion of vertical market differentiation is conducive to improving the stability of high-quality enterprises participating in collusion;in the network effect product market with vertical differentiation,low-quality platform enterprises are more likely to betray and collude.Finally,this paper takes the takeaway platform market as an example to further analyze the collusion stability of the bilateral platform market under the inter-group network effect.Based on the symmetric bilateral platform market model constructed by Ruhmer(2011),combined with the actual asymmetric differentiation characteristics of the bilateral platform market,asymmetric horizontal differentiation parameters are introduced to investigate the asymmetric horizontal differentiation preferences of merchants and consumers.How does the intergroup network effect between each other affect the price collusion stability of food delivery platform companies.This paper finds that when there is a symmetric intergroup network effect between the merchants and consumers of the food delivery platform,that is,when the market demand on both sides has a similar dependence on the market size of the other side,then the collusion stability of the food delivery platform enterprises depends on the overall network.effect,the stronger the overall network effect,the more unstable the collusion of platform enterprises;and when the network effect between the merchants and consumers is asymmetric,under the condition of a certain overall network effect,the expansion of the network effect asymmetry will affect the platform enterprises.The influence of the stability of collusion between the two sides is not monotonous,but is related to the strength of the network effect and the degree of asymmetry of the level difference between the two sides.At this time,if the network effect asymmetry is consistent with the level difference degree asymmetry or the difference is extremely large,the collusion between platform enterprises will become unstable as the network effect asymmetry expands;on the contrary,When the network effect asymmetry is opposite to the level difference asymmetry,but the difference is not large,the collusion between platform enterprises will become stable as the network effect asymmetry expands;when the overall network effect of the two-sided market is strong,When a platform company betrays,the market share limit is reached on both sides of the market.At this time,the stability of collusion between platform companies is not affected by the degree of network effect asymmetry.Aiming at the hidden collusion risk of digital platform enterprises based on algorithm technology under the anti-monopoly policy,this paper starts from the characteristics of the network effect of the platform market,and studies the relevant literature on the implicit collusion of platform enterprises from different perspectives.For the collusion of platform enterprises,especially the behavior of implicit collusion with the help of algorithms,the existing literature mainly starts from the algorithm advantages of platform enterprises,and analyzes how algorithms can improve the transparency of platform market information,alleviate the problem of collusion monitoring and improve the strategic response of enterprises.effect of speed.The research of this paper starts from the fact that the platform market generally has a significant network effect,and studies whether the platform market has a collusion and stability law that is different from the traditional market under the network effect.However,there are few studies discussing the impact of network effects on the stability of corporate collusion.This paper systematically analyzes the platform market collusion problem under the network effect from the perspective of long-term dynamic game.Taking the typical platform market segment industry as a case,it analyzes the law of enterprise collusion under the three most common platform market structures.From the perspective of helping market supervision departments to measure the monopoly risk environmental factors of the digital platform market,it can provide a theoretical basis for the formulation of relevant laws and policies.This paper provides a new theoretical analysis framework for investigating the collusion problem of platform market competition under the network effect.By adjusting the classic Hotelling model,this paper constructs a theoretical model of enterprise competition in the vertically differentiated platform market and the asymmetric two-sided platform market.On the one hand,key parameters are introduced to fully characterize the platform market characteristics under different market structures;on the other hand,the model is simplified to ensure the feasibility of the analysis.Specifically,in the fourth chapter of the research on the vertically differentiated platform market represented by the car-hailing platform,this paper is based on the model processing method of the quality parameters and product network effect parameters introduced by Griva(2011)to the classic Hotelling.The structural characteristics of the market simplify the model reasonably,and finally build a model analysis framework that includes network effects,horizontal differentiation and vertical differentiation.On the basis of retaining the basic horizontal differentiation characteristics of the platform market,this paper realizes the investigation of the influence of network effects on the stability of collusion in the vertically differentiated market.In Chapter 5,the research on the two-sided platform market represented by the takeaway platform,based on the Hotelling model of the two-sided platform market adjustment constructed by Armstrong(2005),the two network effects of the two-sided market are averaged by the network effect.The value and the network effect difference are expressed to examine the influence of the overall network effect and the degree of bilateral market asymmetry on the collusion mechanism of bilateral platform enterprises.Through the above two models,this paper provides an innovative theoretical framework for in-depth analysis of platform market competition and collusion under different market structures.This paper re-examines the effect of horizontal differentiation and vertical differentiation on the stability of enterprise collusion under the network effect,and obtains a different conclusion from the traditional non-network product market,enriching and improving the impact of market differentiation on the stability of enterprise collusion sex research.Product differentiation is the basic structural feature of the market,and it is also a key environmental factor that affects the competition and collusive equilibrium of platform enterprises.From the analysis of the tacit collusion mechanism,the degree of product differentiation has two opposite effects on the stability of collusion between enterprises through two channels.One channel is that the expansion of the degree of product differentiation will reduce the profit of collusion and betrayal of enterprises and improve the stability of collusion,while Another channel is that the expansion of product differentiation will reduce the enterprise’s colluding betrayal punishment and thus inhibit collusion stability.The research of this paper improves the theoretical research on the influence of network effects on enterprise collusion,makes up for the lack of domestic research on the motives and mechanisms of collusion monopoly of platform enterprises under specific network effects,and helps market supervision departments identify the environment of high monopoly risk in the platform market.These factors can guide the direction of optimizing the business environment,provide a theoretical basis for the refined anti-monopoly supervision of the platform market,improve the scientificity and pertinence of anti-monopoly law enforcement,help improve the fair competition system in the platform market,and ultimately promote the healthy development of the platform economy. |
