新葡的京集团8814数字经济理论与政策研讨会会议通知&议程（2023年10月29日 武汉）

本次研讨会由新葡的京集团8814主办，中国信息经济学会基础理论专业委员会协办。会议邀请来自中山大学、暨南大学、南京审计大学等高校的专家学者，围绕社会网络、确认偏见、数据中介、影响者营销等数字经济理论与政策的重大问题，开展交流研讨。

会议时间： 2023年10月29日

会议地点：新葡的京集团8814文澴楼711室

Exclusive Contracts with Both Upstream and Downstream Entry

Abstract:In a continuous-time setting, one upstream incumbent and one downstream incumbent face stochastic arrival of potential entrants with superior efficiency, coming through either the upstream or the downstream market. Entry at any market level raises the flow profit of the incumbent of the other market level by more than it lowers the profit of the incumbent of the same market level, although entry at both levels hurts the flow profits of both incumbents. We first show that even if an exclusive contract cannot be signed, when the hazard rate of entry arrival falls into some intermediate range, there exits an equilibrium of tacit exclusion in which both incumbents voluntarily refuse to deal with any entrant, and entry through both market levels is deterred. Exclusive contract facilitates entry deterrence by widening the parameter range for which entry is blocked. In the case where an incumbent can breach an exclusive contract by compensating the other incumbent for the expectation damages, we characterize conditions under which exclusive contract still facilitates entry deterrence when breach is possible. Finally, we show that even if exclusive contract cannot deter entry, it can benefit the joint profit of the incumbents by delaying entry, in which case one-sided exclusive contract outperforms two-sided exclusive contract.

The Pareto Principle: A Network Formation Model of Social Media Content

Abstract:This study introduces a model to examine network formation on social media platforms. Players decide whether to provide content, its quality, and whom to follow. Every strict equilibrium network exhibits a nested upward-linking structure where different levels of influencers can co-exist. Those in higher tiers provide higher-quality content, followed by players in lower tiers. Under certain parameters, all payoff-dominant strict equilibria conform to the Pareto principle: a small yet significant proportion of players produce a vast majority of content. Unlike prior work where influencers vanish asymptotically, our model demonstrates that influencers, although few in number, can grow proportionally with the population, supporting the emergence of the Pareto principle in both small and large populations. For large populations, a single nested upward-linking network that connects all players can emerge even under heterogeneous preferences over content categories.

Selling Network Information: A Model of the Market for Influencer Marketing

Abstract: A data intermediary sells consumers' social network information, including their influence (in-degree) and/or susceptibility to influence (out-degree), to a monopolist of a network-good. The monopolist then charges consumers personalized prices based on the purchased data. When the intermediary only sells a single dimension and the monopolist can choose the acquisition strategy, the data demand is targeting the most and/or least influential (susceptible) consumers. The intermediary's optimal data pricing induces partial targeting in equilibrium, causing an efficiency loss. If the the monopolist is restricted to random sampling, optimal data pricing induces full acquisition of the consumer list, maximizing the platform's profit, consumer surplus and total welfare while fully extracting the firm's extra profit.

Polarization and populism in the digital era: Experimental evidence from the Russia-Ukraine conflict

Abstract: Individuals’ belief greatly affects decision-making. In the era of the digital economy, it is easier for people to obtain information online. Whether this easier information access accelerate or reduce polarization is a concern of social science researchers and policy makers. This study takes the Russia-Ukraine conflict as the background and uses experiments to explore the impact of information on people's beliefs and behavior. We found that people have a strong confirmation bias, which is aggravated by Populist. Moreover, information consistent with a priori make the individual's belief that they are the "majority" and have the truth, which induce more corresponding behavior.