WHU Theory Seminar

武汉大学经济与管理学院,经济学高级研究论坛 [信息]

2021

  • July 7, 2021, Wednesday
    • Speaker: Zeng, Huaxia (Associate Professor, Shanghai University of Finance and Economics)
    • Title: A Taxonomy of Non-dictatorial Domains
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Han, Lining
    • Abstract: A preference domain is called a non-dictatorial domain if it allows the design of unanimous social choice functions (henceforth, rules) that are non-dictatorial and strategy-proof; otherwise it is called a dictatorial domain. We propose a richness condition on the domain and establish that the unique seconds property (introduced by Aswal, Chatterji, and Sen (2003)) separates non-dictatorial domains from dictatorial domains. The principal contribution of the paper is the subsequent exhaustive classification of all rich non-dictatorial domains based on a simple property of two-voter rules called invariance. The preference domains that constitute the classification are semi-single-peaked domains (introduced by Chatterji, Sanver, and Sen (2013)) and semi-hybrid domains (introduced here) which are two appropriate weakenings of single-peaked domains and which, importantly, are shown to allow strategy-proof rules to depend on non-peak information of voters’ preferences. As a refinement of the classification, single-peaked domains and hybrid domains emerge as the only rich preference domains that force strategy-proof rules to be determined completely by the peaks of voters’ preferences.
    • 曾华夏,上海财经大学经济学院副教授。新加坡管理大学经济学博士。主要研究领域为机制设计,微观经济理论等。有多篇论文发表于Theoretical Economics,Journal of Economic Theory,Games and Economic Behavior等国际期刊。
  • June 9, 2021, Wednesday
    • Speaker: Yu, Jun (tenured Associate Professor, Shanghai University of Finance and Economics)
    • Title: Consumer Search with Blind Buying
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Sun, Xiang
    • Abstract: This article proposes a sequential search model in which consumers freely observe products’ prices and prior values before a search and decide whether and in which order to identify the match values for a positive search cost. We allow consumers to purchase a product without incurring a search cost to inspect the match value, which we call “blind buying”, under which the optimal search policy is no longer as per Weitzman (1979). When the match value has a symmetric distribution, both consumers and firms are indifferent to the search order, conditional on that blind buying does not take place in the first stage. We show that blind buying always increases total welfare, and increases market prices and industrial profits if and only if the first-sample search cost is below a threshold value. An increase in the search cost reduces equilibrium prices. Such a result is consistent with existing price-directed search models, but the underlying mechanisms are different. We also show that being prominent can adversely affect a firm if the match value is asymmetrically distributed, which contrasts the literature.
    • 喻俊,本科毕业于武汉大学经济与管理学院数理经济与数理金融系(高级研究中心),2014年于美国西北大学(Northwestern University)获得经济学博士学位,现为上海财经大学经济学院常任副教授,研究方向包括微观经济理论,产业组织理论和消费者搜寻理论。
  • May 26, 2021, Wednesday
    • Speaker: Li, Xueheng (Assistant Professor, Nanjing Audit University)
    • Title: The Market for Lemons and Liars
    • Time: 14:00–15:30
    • Venue: A208
    • Chair: Sun, Xiang
    • Abstract: Economists have argued that asymmetry information would lead to adverse selection, prohibiting mutually beneficial transactions. Yet, abundant experimental evidence now shows that some individuals will voluntarily and truthfully disclose private information even if it is not in their benefits to do so. Thus, voluntary truth-telling has been proposed to mitigate adverse selection. We examine this conjecture theoretically and experimentally. We consider an environment in which individuals with heterogeneous preferences for truth-telling can self-select into different markets to perform a selling task. The experiment tests the following hypotheses: (i) if naive buyers are many, individuals without lying aversion will self-select into the ‘cheap-talk market’ where they can send any message to the buyer; in contrast, (ii) individuals with a strong preference for truth-telling will self-select into the ‘verifiable-message market’ where they can send only truthful but possibly vague messages; consequently, (iii) adverse selection occurs in the cheap-talk market as if all individuals are material payoff maximizers.
    • 李学恒,2018年博士毕业于英国诺丁汉大学,研究领域包括社会经济网络和行为博弈理论,现为南京审计大学的助理教授。
  • May 21, 2021, Friday
    • Speaker: Kim, Kwanghyun (Assistant Professor, Capital University of Economics and Business)
    • Title: First-Price Auctions with Maxmin Expected Utility Bidders
    • Time: 10:00–11:30
    • Venue: B247
    • Chair: Kim, Daehyun
    • Abstract: This paper studies the first-price auction with independent private valuations, wherein each bidder faces ambiguity about the probability distribution from which the other bidders’ valuations for the item are drawn. Each bidder is ambiguity averse and this ambiguity is represented by a set of priors. In this informational setting, the paper identifies a maxmin Bayesian Nash equilibrium of the auction. It also shows that the bidders’ bids and the seller’s expected revenue increase as the level of the bidders’ ambiguity increases if the bidders’ worst belief under the higher ambiguity level dominates the worst belief under the lower ambiguity level in terms of the inverse hazard rate. Finally, the paper shows that the seller’s expected revenue from the first-price auction is greater than that from the second-price auction.
    • Kwanghyun Kim,首都经济贸易大学国际经济管理学院助理教授。伊利诺伊大学香槟分校经济学博士。主要研究领域为机制设计,微观经济理论等。
  • May 19, 2021, Wednesday
    • Speaker: Sun, Yang (Associate Research Fellow, Sichuan University)
    • Title: Myopic Formation of Networks
    • Time: 14:00–15:30
    • Venue: A208
    • Chair: Sun, Xiang
    • Abstract: We study the problem of designing network sequentially and myopically when agents play a complementary network game. In each period, the planner connects two unlinked agents in the network formed by previous stages to achieve the highest equilibrium welfare. We show that the network formation process is unique in the sense that the formed network is quasi-complete in each period regardless the strength of complementary effect. This result refines the prediction of (globally) efficient network in the literature by discriminating nested split graphs. Finally, we show that when the strength of network effect is small and the total number of links is large, both myopically and globally efficient network is quasi-complete.
    • 孙阳,四川大学经济学院特聘副研究员,研究领域为博弈论、网络经济学。他的学术工作发表于Economic Theory、Economic Modelling等经济学重要期刊。
  • May 12, 2021, Wednesday
    • Speaker: Wu, Xingye (Assistant Professor, Tsinghua University)
    • Title: A Notion of Voting Complexity (joint with Qinggong Wu)
    • Time: 14:00–15:30
    • Venue: B224
    • Chair: Sun, Xiang
    • Abstract: We develop a measure of complexity of a voting problem in terms of the dimensionality of its intermediate type space introduced by Grandmont (1978). A voting problem with a lower dimensionality is less vulnerable to the problem of voting cycles and more likely to have a candidate that has a decent popular support.
    • 吴星晔,2018年毕业于哥伦比亚大学,现为清华经管学院经济系助理教授,研究兴趣包括微观经济学理论,机制设计和匹配理论。
  • May 7, 2021, Friday
    • Speaker: Xu, Menghan (Assistant Professor, Xiamen University)
    • Title: Incentivizing Organ Donation Under Blood-Type Compatibility Constraints: Theory and Experiment
    • Time: 14:00–15:30
    • Venue: B247
    • Chair: Kim, Deahyun
    • Abstract: This paper studies the efficacy of the donor-priority rule in promoting deceased organ donation under blood-type compatibility constraints in both theory and the laboratory. Compared with an allocation policy in which transplantations are operated only within the same blood-type group, we find that transferring organs across blood-type compatible groups discourages the donation incentives of hard-to-match agents, and reduces the supply of the more widely acceptable type of organs. Meanwhile, the easy-to-match agents have higher incentives to donate. At the aggregate level, our theoretical and experimental results both suggest that the aggregate donation rate is lower under allocation policies that allow blood-type compatible transplants among different blood-type groups.
    • 许梦涵,厦门大学经济学院与王亚南经济研究院助理教授。加州大学洛杉矶分校经济学博士。主要研究领域为微观经济理论、机制设计、产业组织理论等。主要研究成果发表于Journal of Economic Theory等国际学术期刊上。
  • April 30, 2021, Friday
    • Speaker: Song, Yangbo (Assistant Professor, The Chinese University of Hong Kong Shenzhen)
    • Title: Global Manipulation by Local Obfuscation
    • Time: 14:00–15:30
    • Venue: B249
    • Chair: Kim, Daehyun
    • Abstract: We study adversarial information design in a regime-change context. A continuum of agents simultaneously choose whether to attack the current regime. The attack succeeds if and only if the mass of attackers outweighs the regime’s strength. A designer manipulates information about the regime’s strength to maintain the status quo. Our optimal information structure exhibits local obfuscation: some agents receive a signal matching the regime’s true strength, and others receive an elevated signal professing slightly higher strength. This policy is the unique limit of finite-signal problems. Public signals are strictly suboptimal, and in some cases where public signals become futile, local obfuscation guarantees the collapse of agents’ coordination.
    • 宋阳波,本科毕业于香港大学经济金融系,于加州大学洛杉矶分校获得经济学博士学位,现于香港中文大学(深圳)经管学院任助理教授。研究方向为博弈论、网络经济学和信息经济学,论文见于Journal of Economic Theory, Games and Economic Behavior, Economic Theory, Journal of Economic Behavior and Organization等国际知名期刊。目前主要研究内容包括超模博弈中的信息设计,网络中的信息不对称与合约设计,意识局限对策略行为的影响等。
  • March 24, 2021, Wednesday
    • Speaker: Chen, Wanyi (Associate Research Fellow, University of Science and Technology of China)
    • Title: Strategic Hospital Runs
    • Time: 14:00–15:30
    • Venue: B249
    • Chair: Wei, Lijia
    • Abstract: Hospital runs are of primary concern in a pandemic and are especially devastating when non-severe patients crowd out severe ones. We study a rushing game for hospital service. The fear of future scarcity may drive non-severe patients to inefficiently seek early treatment. The forward-looking nature induces a chain effect–expecting a far future run realizes the near future run, which in turn induces the current run. This feature triggers the run long before the capacity is insufficient for severe patients. Due to strategic rushing, a higher capacity may induce more devastating hospital crowding out. On the other hand, inefficient waiting can also occur. A planner would allocate a fraction of medical resources to non-urgent patients to alleviate future congestion, but individuals do not consider this externality of future overload. Besides, the strategic complementarity can also lead to self-fulling runs. We characterize conditions for such scenarios to occur.
    • 陈琬祎,中国科学技术大学管理学院特任副教授/特任副研究员。2018年毕业于美国威斯康辛大学麦迪逊分校,获经济学博士学位。2011年毕业于武汉大学数理经济与数理金融实验班,获得金融学与应用数学学位。主要研究领域为信息经济学、博弈论,和应用微观经济学。

2020

  • December 16, 2020, Wednesday
    • Speaker: Yao, Zhiyong (Associate Professor, Fudan University)
    • Title: Upstream Collusion with Down Stream Compensation
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Ding, Yucheng
    • Abstract: Many cartels exist in supply chains with powerful buyers. These buyers have the incentive and information to report the cartel to the antitrust authorities or sue the cartel members. Therefore, successful upstream collusions not only need to prevent the collusive members to deviate, but also has to compensate the downstream firms. Using repeat game theory, this paper studies the stability of upstream collusion, taking into account the downstream compensation. Different from the standard collusion theory, the relationship between cartel incidence and market concentration is likely to be non-monotonic, or it is the inverted U-shape.
    • 姚志勇:复旦大学管理学院产业经济学系副教授,北京大学经济学学士和硕士,美国加州大学洛杉矶分校经济学博士,主要从事产业经济学、管理经济学教学和科研工作,论文发表于Rand Journal of Economics,Journal of Mathematical Economics等学术期刊,主持国家自然科学基金面上项目等多项国家与省部级科研项目。

2019

  • November 21, 2019, Thursday
    • Speaker: Wang, Tao (Assistant Professor, Nanjing Audit University)
    • Title: Strong Stochastic Dominance
    • Time: 14:00–15:30
    • Venue: A204
    • Chair: Li, Xiaoxi
    • Abstract: We generalize the monotone likelihood ratio property of univariate random variables. We say that one distribution strongly stochastically dominates another if the former is a convex transformation of the latter. The main contribution of this paper is the introduction of an equivalent condition phrased in terms of expectations. Several economic applications of this equivalence condition are given. These applications include monotone comparative statics under uncertainty, Bayesian learning and dynamics, pricing of risky assets, implications to a portfolio’s value-at-risk and to production expansions.
    • 王韬,南京审计大学社会与经济研究院助理教授,于纽约州立大学石溪分校获得博士学位,在特拉维夫大学进行过博士后研究。研究领域为信息经济学、产业组织理论、博弈论。部分研究成果已在国际期刊International Journal of Industrial Organization,Review of Industrial Organization上发表。
  • November 7, 2019, Thursday
    • Speaker: Lu, Yuanzhu (Central University of Finance and Economics)
    • Title: 挂靠投标腐败对招标方有害吗?
    • Time: 15:00–16:30
    • Venue: B249
    • Chair: Shen, Bo
    • Abstract: 本文在第一分值多维招投标的框架下,研究了受贿的招标代理人和行贿者勾结进行串标,即招标代理人允许行贿者挂靠投标这一腐败形式对于招投标活动的影响。研究发现,挂靠投标腐败对竞标者投标组合中承诺的质量没有影响。行贿者的低评分竞标函数比诚实竞标者的更加弱势,在一定的条件下,行贿者的高评分竞标函数比诚实竞标者的更加激进。当招标代理人和出借资质的企业要求从行贿者处获得的回报占行贿者所获额外利润的比例增加时,行贿者的高评分竞标策略和低评分竞标策略都变得更加弱势。挂靠投标腐败的存在降低了招投标活动的效率。在行贿者的高评分竞标函数比诚实竞标者的更加激进这一合理假设下,行贿者在招投标中获胜的概率增加,诚实竞标者的获胜概率和期望利润都下降,招标人的期望效用可能增加也可能下降。
    • 卢远瞩,中央财经大学中国经济与管理研究院经济学教授,博士生导师,中央财经大学学术委员会理论经济学部委员,专业技术职务评审委员会经济学科组评委。北京大学理学学士、经济学双学士、经济学硕士,新加坡国立大学经济学博士。主要研究领域为产业组织理论,在国际国内经济学期刊发表论文近30篇,论文见于International Journal of Industrial Organization, Oxford Economic Papers,《经济学(季刊)》等著名期刊。2011年入选教育部新世纪优秀人才支持计划,2014年获得霍英东教育基金会第14届高等院校青年教师奖三等奖,2017年获得北京市优秀教师称号。
  • September 18, 2019, Wednesday
    • Speaker: Solan, Eilon (Professor, Tel Aviv University)
    • Title: Optimal Dynamic Inspection
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Li, Xiaoxi
    • Abstract: We study a discounted repeated inspection game with two agents and one regulator. Both agents may profit by violating certain rules, while the regulator can inspect at most one agent in each period, inflicting a punishment on an agent who is caught violating the rules. The goal of the regulator is to minimize the discounted number of violations, and she has a commitment power. We identify the regulator’s optimal inspection strategy, and show that it significantly outperforms the inspection strategies studied in the literature.
    • Eilon Solan现为以色列特拉维夫大学统计与运筹学系教授,世界知名的博弈论、概率论专家,在随机博弈、马尔可夫决策过程、社会学习等领域做出了众多突出科学贡献。他的研究成果发表于PNAS、Annals of Probability、Annals of Statistics, Econometrica、Operations Research、SIAM Control and Optimization、Mathematics of Operations Research、Journal of Economic Theory、Games and Economics Behavior等高水平学术期刊。多年来一直担任多个国际学术期刊编委,目前Eilon Solan教授还是以色列和特拉维夫大学多个拔尖学生科学项目的负责人,如Beno Arbel Program,Good To Know project, training program of the Israeli team to the International Mathematics Olympiad。Eilon Solan教授也是多个计算机技术专利的共同发明人,他与同事在1997年最早申请了如今广泛使用的验证码专利技术CAPTCHA。
  • June 27, 2019, Thursday
    • Speaker: Miao, Bin (Professor, Shanghai University of Finance and Economics)
    • Title: Multiple-Switching Behavior in the Elicitation of Risk Preferences
    • Time: 10:30–11:30
    • Venue: A208
    • Chair: Sun, Xiang
    • Abstract: While it is commonly observed that subjects switch multiple times in the choice list elicitation of risk preference, little has been done to systematically examine the nature of this multiple switching behavior (MSB). We differentiate two types of MSB: for odd (even) MSB, subjects initially choose options on the left hand side, and eventually switch to options on the right (left) hand side. In two experiments, we observe that subjects with higher frequency of odd MSB are more likely to deliberately randomize in repeated choices presented three times in a row (Agranov and Ortoleva, 2017), and to exhibit Allais-type behavior as well as to satisfy reduction of compound lottery axiom at the same time. By contrast, we show that subjects with higher frequency of even MSB are more likely to violate first-order stochastic dominance. Our results support models of deliberate randomization to partially account for MSB, and enable a further discrimination among models of stochastic choice.
  • May 31, 2019, Friday
    • Speaker: Dessi, Roberta (Toulouse School of Economics)
    • Title: Shame, Guilt and Self-Confidence: an Economic Analysis
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Dr. Li, Xiaoxi
    • Abstract: The evidence from anthropology, psychology and economics shows that sensitivity to the emotion of shame varies across cultures. So does the tendency to exhibit overconfidence. This paper explores the connection between these two observations. It also sheds light on the, related, role of the sensitivity to guilt. Shame and guilt have been portrayed as alternative mechanisms to enforce cooperation. We focus on a key difference between shame and guilt: shame is less sensitive to an individual’s private information, making it a rather blunt instrument, while guilt is more vulnerable to manipulation by the self (e.g. excuses, selective attention, exploiting moral wiggle room…). Shame and guilt influence individual behaviour in a variety of dimensions, including their effect on individuals’ incentives to pursue long-term goals and invest in new projects. Taking this into account, we investigate how reliance on guilt versus shame interacts with a different psychological incentive mechanism: overconfidence. We investigate our model’s predictions using data on differences in self-confidence and in shame and guilt sensitivity across countries, as well as individual-level data on migrants.
  • May 24, 2019, Friday
    • Speaker: Li, Sanxi (Professor, Renmin University of China)
    • Title: Sharing Consumers’ Data in Vertically Differentiated Duopoly
    • Time: 15:00–16:30
    • Venue: A208
    • Chair: Han, Lining
    • Abstract: This paper investigates the incentives and effects of competing firms sharing consumers’ personal information in a duopoly market, where two firms sell vertically differentiated products. We derive firms’ pricing strategies and welfares of all parties under different information structures. And we show that only when firm with less competitive advantage has all consumers’ information will sell part of consumers’ personal information to its competitor to maximize the total revenue. The smaller the competitive advantage of the firm, the more personal information of consumers will be sold to their competitors. To maximize the profits of the whole industry and also social welfare, all consumers’ personal information should be owned by the firm with competitive advantage.
  • May 9, 2019, Thursday
    • Speaker: Zhang, Jun (Assistant Professor, Nanjing Audit University)
    • Title: Fractional Top Trading Cycle
    • Time: 14:00–15:30
    • Venue: B249
    • Chair: Han, Lining
    • Abstract: We generalize the Top Trading Cycle mechanism to solve random assignment problems. Specifically, we study the fractional endowment exchange problem in which each agent may own fractional amounts of multiple objects and each object may be owned by multiple agents. We propose a class of mechanisms based on a linear programming method. At every step, our mechanisms let agents point to most preferred objects and objects point to all of their owners. We use a linear equation system to describe how to trade the network generated at every step. Interestingly, the equation system is an instance of the classical Leontief input-output model so that its solutions must exist. We provide an intuitive explanation of our mechanisms: at every step, there exist disjoint absorbing sets in the generated network and agents in each absorbing set trade endowments only among themselves. All of our mechanisms are individually rational and sd-efficient. We characterize those mechanisms satisfying desirable fairness properties including equal-endowment no envy and stronger notions. We apply the mechanisms to solve real-life problems including school choice with weak priorities and time bank.

2018

  • December 21, 2018, Friday
    • Speaker: Cheng, Chen (Assistant Professor, Johns Hopkins University)
    • Title: Stable Allocations with Network-Based Comparisons
    • Time: 15:30–17:00
    • Venue: A208
    • Chair: Han, Lining
    • Abstract: We consider a model in which an agent’s payoff is based on her (local) ranking, i.e., the ranking of her allocation among her neighbors’ in the network. An allocation is stable if it is not revoked under α-majority voting; that is, there exists no alternative allocation, such that a fraction of at least α of the population have their rankings strictly improved under the alternative. We find a sufficient and necessary condition for a network to permit any stable allocation: the network has an independent set of size at least (1 − α) of the population. A network is more permissive if it permits stable allocation for a larger set of α. We then characterize the size of the largest independent set for Erdős–Rényi random networks, which reflects how permissive a network is: for large enough population, the level of permissibility solely depends on the expected degree. We provide several interesting comparative statics results: more connected networks, more populated networks (with a fixed link probability), or more homophilous networks are less permissive. Given expected degree, whether a network is segregated or integrated would not affect the level of permissibility. We generalize our model to arbitrary blocking coalitions and provide a sufficient and necessary condition for this case. We also extend the model to directed networks.
  • December 21, 2018, Friday
    • Speaker: Xing, Yiqing (Assistant Professor, Johns Hopkins University)
    • Title: Screening with Network Externalities
    • Time: 14:00–15:30
    • Venue: A208
    • Chair: Xiao, Mingjun
    • Abstract: We develop a model in which a profit-maximizing monopoly sells a product with positive network externalities and optimally screen buyers’ network information: their susceptibility (out-degree) and influence (in-degree). We characterize the optimal allocation for both the case of directed networks where each buyer’s influence and susceptibility are independent, and the case of undirected networks where the two are identical. In the case of directed networks, we show the optimal allocation can only depend on a buyer’s susceptibility and linear in virtual type (susceptibility) with quadratic intrinsic value. In the case of undirected networks, we disentangle the different effects of influence and susceptibility on optimal allocation and show with quadratic intrinsic value, the allocation is a linear combination of a buyer’s type and virtual type. Then we contrast the model with complete information pricing and pure screening and show that apart from the screening effects, positive network externalities increase each buyer’s allocation at the optimal selling mechanism. We also extend the model to accommodate for weak positive affiliation between a buyer’s influence and susceptibility, and the situation where influence and susceptibility are endogenous to the optimal allocation.
  • November 12, 2018, Monday
    • Speaker: He, Wei (Assistant Professor, The Chinese University of Hong Kong)
    • Title: Dynamic Project Assignment
    • Time: 10:30–11:30
    • Venue: A208
    • Chair: Sun, Xiang
    • Abstract: We consider a project assignment problem where a Principal needs to assign multiple projects to a long-lived Agent. The Agent is privately informed about her cost, which evolves stochastically over time. To fully characterize the optimal mechanism, we identify the key trade-off of the Principal, which is the comparison between the benefit from an immediate assignment at high cost and the payoff from a delayed assignment at low cost. We show that the capacity constraint can reduce the payoff of the Principal and create a “hold-up” problem by comparing the limit of the optimal payoffs of the Principal when the capacity constraint is present, with the Principal’s optimal payoff when the capacity constraint is absent.
  • October 25, 2018, Thursday
    • Speaker: Wang, Tong (Lecturer, The University of Edinburgh)
    • Title: Economics and Corporate Finance in the World of Blockchain
    • Time: 10:00–11:30
    • Venue: A208
    • Chair: Li, Xiaoxi
    • Abstract: This talk aims to give a brief introduction about the principle and mechanism of blockchain that may be of interest for economists and social scientists. It will also describe a game-theoretical framework of Initial Coin Offering and the points that the regulatory agencies may concern. Finally, some potential research topics with blockchain implementation will be addressed, which make a connection between the theory of corporate finance and the industrial practice.
  • September 19, 2018, Wednesday
    • Speaker: Feng, Xin (Assistant Professor, University of International Business and Economics)
    • Title: Information Disclosure in All-pay Auctions with Costly Entry
    • Time: 14:00–15:30
    • Venue: B247
    • Chair: Shen, Bo
    • Abstract: In this paper, we accommodate costly entry of contestants and examine the optimal information disclosure in a two-player all-pay contest. The contest organizer commits to an information policy to disclose the characteristics of the contest prize before contestants make their entry decisions. With free entry, we show that full concealment always induces higher aggregate effort than full disclosure policy, due to the property of “full rent dissipation”.However, by taking into account costly entry, full disclosure could dominate full concealment policy by attracting contestants. entries.We further consider random disclosure and identify the optimal degree of transparency. Depending on the range of entry cost, full disclosure, full concealment, and random disclosure policies could be optimal. In particular, it is ex ante optimal for the contest organizer to commit to a more transparent information policy as the entry cost rises. Our results indicate that entry incentive plays a crucial role in the design of information disclosure.
  • September 3, 2018, Monday
    • Speaker: Wang, Yun (Assistant Professor, Xiamen University) and Lee, Jong Jae (Assistant Professor, Wuhan University)
    • Title: Bayesian Persuasion: Theory and Applications
    • Time: 09:00–12:00
    • Venue: B247
    • Chair: Li, Xiaoxi
    • Abstract: This mini course covers several topics on Bayesian persuasion theory and its applications. In the main part of this lecture, Prof. Yun Wang first presents the basic model of Bayesian persuasion à la Kamenica and Gentzkow (AER 2011) and then talks about the extension to the situations of multiple receivers and of privately informed receivers. At the end, Prof. Jong Jae Lee discusses an application of the Bayesian persuasion model to the advertising problems in the marketing science.
  • June 28, 2018, Thursday
    • Speaker: Xu, Zibo (Assistant Professor, Singapore University of Technology and Design)
    • Title: Stability of Settled Equilibria
    • Time: 10:00–11:30
    • Venue: B249
    • Chair: Li, Xiaoxi
    • Abstract: This paper defines a rationally tenable block and a rationally settled equilibrium in a symmetric game. Examples and properties for evolutionary stability are shown.
  • May 17, 2018, Thursday
    • Speaker: Liu, Bin (Assistant Professor, The Chinese University of Hong Kong, Shenzhen)
    • Title: Sequential Screening with Hidden Actions
    • Time: 14:00–15:30
    • Venue: B226
    • Chair: Sun, Xiang
    • Abstract: One common insight in the sequential screening literature (e.g., Courty and Li, 2000, and Eső and Szentes, 2007) is that the allocation (implemented in the second stage) is in general discriminatory over the first stage types. In this paper, we study how introducing a first-stage type-enhancing hidden action of the agent would affect the degree of discrimination at the optimum in a two-stage procurement setting where the agent can make costly unobservable investment to improve his first stage type, which is the distribution of his second-stage realized private cost of delivering the product. The principal’s goal is to minimize the expected procurement cost. We find that the introduction of moral hazard unambiguously mitigates the allocative discrimination in the second stage. In particular, the second stage mechanism can even be non-discriminatory when the marginal cost of investment is small enough.
  • April 26, 2018, Thursday
    • Speaker: Cao, Zhigang (Professor, Beijing Jiaotong University)
    • Title: A network game of dynamic traffic
    • Time: 14:00–15:30
    • Venue: B226
    • Chair: Sun, Xiang
    • Abstract: We study a network congestion game of discrete-time dynamic traffic of atomic agents with a single origin-destination pair. Any agent freely makes a dynamic decision at each vertex (e.g., road crossing) and traffic is regulated with given priorities on edges (e.g., road segments). We first constructively prove that there always exists a sub-game perfect equilibrium (SPE) in this game. We then study the relationship between this model and a simplified model, in which agents select and fix an origin-destination path simultaneously. We show that the set of Nash equilibrium (NE) flows of the simplified model is a proper subset of the set of SPE flows of our main model. We prove that each NE is also a strong NE and hence weakly Pareto optimal. We establish several other nice properties of NE flows, including global First-In-First-Out. Then for two classes of networks, including series-parallel ones, we show that the queue lengths at equilibrium are bounded at any given instance, which means the price of anarchy of any given game instance is bounded, provided that the inflow size never exceeds the network capacity. (joint work with Bo Chen, Xujin Chen, and Changjun Wang)
  • April 24, 2018, Tuesday
    • Speaker: Zhou, Junjie (Assistant Professor, National University of Singapore)
    • Title: Coordination on Networks
    • Time: 13:00–14:30
    • Venue: B226
    • Chair: Sun, Xiang
    • Abstract: We study a coordination game among agents on a network, who choose whether or not to take an action that yields value increasing in the actions of neighbors. In a standard global game setting, players receive noisy information of the technology’s common state-dependent value. We show the existence and uniqueness of a pure equilibrium in the noiseless limit. We derive limiting cutoffs, which allocate players into coordination sets, within members take a common cutoff strategy and are path connected. We provide necessary and sufficient conditions for agents to inhabit the same coordination set. The strategic effects of perturbations to players’ underlining values are shown to spread throughout but be contained within the perturbed players’ coordination sets. Welfare properties are investigated.

2017

  • May 8, 2017, Monday
    • Speaker: Tang, Qianfeng (Associate Professor, Shanghai University of Finance and Economics)
    • Title: Weak stability and Pareto efficiency in school choice
    • Time: 15:30–17:00
    • Venue: B127
    • Chair: Sun, Xiang
    • Abstract: We propose a new notion of weak stability for two-sided matching problems. A matching is said to be weakly stable if matching any of its blocking pairs inevitably creates new blocking pairs. We then apply this concept to school choice and study its compatibility with the Pareto efficiency of students’ welfare. Our main result shows that if a matching Pareto dominates the student-optimal stable matching for the students, then it is weakly stable if and only if it is more stable than the outcome of Kesten’s efficiency-adjusted deferred acceptance mechanism (EADAM) for some consenting constraint. We also provide a test for weak stability by showing that a matching is weakly stable if and only if it is as stable as the EADAM outcome which uses its set of blocking pairs as the consenting constraint.
  • April 10, 2017, Monday
    • Speaker: Zheng, Jie (Assistant Professor, Tsinghua University)
    • Title: Multi-period Matching with Commitment
    • Time: 15:30–17:00
    • Venue: B127
    • Chair: Sun, Xiang
    • Abstract: Many multi-period matching markets exhibit some level of commitment. That is, agents’ ability to terminate an existing relationship may be restricted by cost of breakups, binding contracts or social norms. This paper models matching markets with three types of commitment, defines corresponding notions of stability and examines the existence of stable mechanisms, as well as specifies sufficient conditions for efficiency, strategy-proofness and other properties. Firstly, the market with full commitment most closely resembles the static matching market, where most of the results, such as existence of stability, hold in the most general class of preferences. However, there is no dynamically stable spot rule, which only depends on spot markets, unless agents are extremely impatient. Secondly, for the models with two-sided commitment or one-sided commitment, desirable properties that are valid under the setup with a fixed set of individuals may not hold when arrivals and departures are introduced, and three approaches are proposed to deal with this issue. Whenever a dynamically stable matching exists, we construct an algorithm building upon the Deferred Acceptance algorithm of Gale and Shapley (1962) to characterize such a matching outcome. Moreover, as extensions, we discuss the case with no commitment and conduct welfare comparisons among cases with different types of commitment.
  • March 30, 2017, Thursday
    • Speaker: Wang, Zhewei (Professor, Shandong University)
    • Title: Multi-dimensional All-pay Contests
    • Time: 15:30–17:00
    • Venue: B247
    • Chair: Sun, Xiang
    • Abstract: Multi-dimensional contests refer to situations where players compete by exerting efforts in multiple dimension, which is commonplace in the real world. In a two-player two-dimension all-pay contest model, we derive and compare the optimal grand multi-dimensional contest and the optimal separate single-dimensional contests. We find that the former is preferred/indifferent to the latter for the contest designer when her payoff function takes a multiplicative/additive form. Intuitively, when the payoff function takes a multiplicative form, effort level in one dimension has an externality effect to the effectiveness of effort making in another dimension. In a grand two-dimensional contest each player bids efforts in two dimensions cooperatively where the externality effect is taken into consideration.
  • March 23, 2017, Thursday
    • Speaker: Zhang, Wenzhang (tenured Associate Professor, Shanghai University of Finance and Economics)
    • Title: Self-Evident Events and the Value of Linking
    • Time: 13:00–14:30
    • Venue: B251
    • Chair: Sun, Xiang
    • Abstract: We propose a theory of linking in long-term relationships that is based on the notion of self-evident event, which describes what becomes “public” at the end of a stage game where players observe both public and private information. We obtain a tight bound on the average per-period efficiency loss that must be incurred to enforce a stage-game outcome throughout a T-period repeated game when T is large. Our results apply to all monitoring structures and strategy profiles. They explain the inefficiency result in Abreu, Milgrom, and Pearce (1991), as well as the approximate-efficiency results in Compte (1998), Obara (2009), and Chan and Zhang (2016).
  • March 20, 2017, Monday
    • Speaker: Yang, Ming (Assistant Professor, Duke University)
    • Title: Coordination and Continuous Choice
    • Time: 10:00–10:30
    • Venue: B127
    • Chair: Sun, Xiang
    • Abstract: We study a coordination game where players choose what information to acquire about payoffs prior to the play of the game. We allow general information acquisition technologies, modeled by a cost functional defined on information structures. A cost functional satisfies continuous choice if players choose a continuous decision rule even in a decision problem with discontinuous payoffs. If continuous choice holds, there is a unique equilibrium; if it fails, there are multiple equilibria. We show how continuous choice captures the idea that it is sufficiently harder to distinguish states that are close to each other relative to far away states.
  • March 9, 2017, Thursday
    • Speaker: Sun, Yifei (Assistant Professor, University of International Business and Economics)
    • Title: Maskin Meets Abreu and Matsushima
    • Time: 15:30–17:00
    • Venue: B127
    • Chair: Sun, Xiang
    • Abstract: Maskin (1977, 1999) proposes a well known monotonicity condition, which we refer to as Maskin monotonicity and shows it to be necessary and almost sufficient for Nash implementation. Although many implementation results using refinements of Nash equilibrium can dispense with Maskin monotonicity, a recent development in the literature shows that if we were to make implementation robust to information perturbations, Maskin monotonicity would come back as a necessary condition. Looking at environments with monetary transfers and quasiliner preferences, we show that Maskin monotonicity is not only necessary but sufficient for Nash implementation by finite mechanisms. It is easy to see that finite mechanisms are robust to information perturbations. To obtain this result, we construct a novel finite mechanism that exploits the notion of dictator lotteries of Abreu and Matsushima (1992) and we apply it to Nash implementation. Our mechanism does not use the integer games or anything alike and takes care of mixed strategies explicitly. We also extend our result to the case of social choice correspondences, two agents, and rationalizable implementation of social choice functions.

2016

  • November 18, 2016
    • Speaker: Huangfu, Bingchao (Assistant Professor, Zhongnan University of Economics and Law)
    • Topic: A Tale of Two Lemons: Multi-good Dynamic Adverse Selection
    • Time: 13:30–15:00
    • Venue: B129
    • Chair: Chen, Bo
    • Abstract: This paper studies the role of cross-market information spillovers in a multi-good dynamic bargaining problem with interdependent values. More precisely, in an environment where a seller has two heterogeneous goods for sale in two markets and is better informed than the potential buyers about the qualities of the goods, we investigate how the information revealed through (non-)trade of one good affects the probability of trade of the other good, and its consequences to the trading dynamics and patterns of specialization. Our main finding is that when the qualities of the two goods are sufficiently negatively correlated and the seller is patient, then even if adverse selection precludes first-best efficiency for both goods, it is mitigated as sequential trade occurs quickly through the seller’s endogenous signaling motive, as long as buyers in one market observe the (non-)trading outcome in the other market. As a consequence, sellers have an incentive to specialize in one of the two goods before playing the bargaining game with the buyers, in such a way to endogenously generate the required negative correlation between the qualities of the two goods. In contrast, without such cross-market observability and subsequent specialization, i.e., endogenous negative correlation, there is either bargaining delay or impasse in both markets as in the standard dynamic adverse selection problem.
  • November 3, 2016
    • Speaker: Wu, Jiemai (Assistant Professor, The University of Sydney)
    • Topic: Beneficially Imperfect Persuaders
    • Time: 10:00–11:30
    • Venue: B129
    • Abstract: When a decision maker’s (DM’s) choice depends on the information provided by persuaders, does the DM benefit from that information? I address this question in the context of a Bayesian persuasion game in which independent persuaders with no private information try to persuade a DM by gathering information using verifiable tests. All persuaders want the DM to switch her action from a default action to a new action, but whether the DM also finds it optimal to switch depends on the state of the world. The persuaders strategically design tests that may be biased towards the new action and that best respond to the test designs of the other persuaders. I show that although the DM never benefits when there is only one persuader, there always exist strict equilibria with high payoffs for the DM when there is more than one persuader, even if the persuaders have perfectly aligned incentives. Moreover, in these equilibria, persuaders choose noisy tests that sometimes misreport their desired state as the undesired one.
  • September 28, 2016
    • Speaker: Zhao, Xiaojian (Assistant Professor, The Hong Kong University of Science and Technology)
    • Topic: Incentive-Compatibility in Financial Contracting with Limited Liability
    • Time: 10:00–11:30
    • Venue: B247
    • Abstract: In the presence of limited liability, the incentive compatibility constraints in financial contracting models with asymmetric information are weaker than assumed in much of the literature. In this paper, we identify the problem that has been overlooked in the literature and provide a rigorous proof of optimality of debt contracts under fairly general assumptions.
  • June 6, 2016
    • Speaker: Qu, Xiangyu (University of Paris 2)
    • Topic: Bayesian Aggregation with Heterogenous Beliefs and Values
    • Time: 14:30–16:00
    • Venue: B127
    • Abstract: Bayesian theory for individual decision making under uncertainty prescribes that individuals posit a utility function, a probability over events and evaluate each act on the basis of its expected utility. We attempt to generalize the model to social decision making. The aggregation rules we consider are both society’s belief and values are the affine aggregation of individuals beliefs and values, respectively. It is well-known that standard Pareto condition is not compatible with separate aggregation. Two natural extended Pareto condition are suggested. We show that Invariant Pareto condition is equivalent to separate aggregation under Anscome-Aumann setting and Hedging Pareto condition is equivalent to separate aggregation under Savage setting.

2015

  • December 10, 2015
    • Speaker: Chen, Yu (Assistant Professor, Nanjing University)
    • Topic: Existence of Optimal Contracts with the Inclusion of Observable Actions in Generalized Moral Hazard Problems
    • Time: 15:00–16:30
    • Venue: B127
    • Abstract: We provide a generalized model concerning the one-shot pure-strategy moral hazard contracting game with the inclusion of observable actions as well as unobservable actions. The outcome, action, and reward spaces are assumed to be all metrizable and compact and allowed to be uncountable and multi-dimensional. We find that employing observable-action-and-outcome-contingent contracts is strategically equivalent to employing pure outcome-contingent contracts, as long as the principal can specify and enforce individual rational observable actions to the agent. The space of feasible contracts is assumed to be (sequentially) closed under the topology of point-wise convergence. We do not need any other a priori technical assumptions on the contract function space. We then propose conditions under which the solution to such a principal-agent problem exists.
  • October 30, 2015
    • Speaker: Xiao, Mingjun (Assistant Professor, Wuhan University)
    • Topic: Mechanism Design with Interdependent Valuations and Semi-exclusive SignalsMechanism Design with Interdependent Valuations and Semi-exclusive Signals
    • Time: 14:00–15:30
    • Venue: B127
    • Abstract: This paper approaches the classic implementation problem with interdependent valuations in a new way. Instead of exploring conditions on preferences, we introduce a semi-exclusive information structure that can help implement efficient or inefficient social choice rule in generic environments. Semi-exclusive information allows agents to observe noisy signals about their opponents’ payoff types. This piece of information can provide a tool for the designer to verify other agents’ private information. Thanks to this tool, we could restore the implementation of efficiency that would not have been possible following the routine method of finding global or local sorting conditions. We study generic environments that include settings with preferences not satisfying “single crossing conditions,” or other similar sorting conditions. The role of semi-exclusive signal is targeted to align the incentive constraints. We explore the implementability of efficient rule and other properly specified rules both when this information structure is static and when it is dynamic. While both setups can implement general allocation rules, the static setting sheds light on Crémer and McLean (1985,1988)’s utilization of correlation and the dynamic setting steps away from Crémer and McLean’s world and explores the correlation after the allocation decisions.
  • May 21, 2015
    • Speaker: Zhang, Yongchao (Associate Professor, Shanghai University of Finance and Economics)
    • Topic: On Pure-strategy Equilibria in Games with Correlated Information
    • Time: 15:30–17:00
    • Venue: B226
    • Chair: Sun, Xiang
    • Abstract: Aumann (1974) showed that the set of independent objective pure-strategy equilibrium payoffs of a suitably formulated correlated information game coincides with the set of mixed-strategy Nash equilibrium payoffs of the original complete information game. A decisive example of Radner-Rosenthal (1982) questioned the hypothesis of this result. In this paper, we address the criticism, and in resolution, establish the existence of pure-strategy Bayesian-Nash equilibrium in a class of correlated information games. We also show that a saturated information structure is necessary to guarantee the existence of equilibrium in a small class of such games.
  • April 14, 2015
    • Speaker: Zhou, Junjie (Associate Professor, Shanghai University of Finance and Economics)
    • Topic: Competitive Multi-sided Platforms
    • Time: 15:30–17:00
    • Venue: B127
    • ​Chair: Sun, Xiang
    • Abstract: This paper provides a model of competition with an arbitrary number of platforms with multi sides. We show the existence and uniqueness of equilibrium prices for any degree of externality among different sides. Under symmetry condition, the equilibrium price for each side can be conveniently decomposed into three parts: cost, premium due to product differentiation, and discount due to cross subsidies. We also explore some comparative statics and investigate the effect of mergers on prices, consumer welfare, firm profit etc.

2014

  • December 25, 2014
    • Speaker: Rong, Kang (Associate Professor, Shanghai University of Finance and Economics)
    • Topic: Public Good Provision with Voting
    • Time: 15:30–17:00
    • Venue: B129
    • Chair: Sun, Xiang
    • Abstract: This paper studies the public good provision problem, in which a public good provision mechanism can be enforced among a group of agents only if the mechanism can be approved by the agents under a prespecified alpha majority rule. We find that as long as the voting rule is not the unanimity rule, then the first-best efficient level of the public good can be achieved even when the economy is large.
  • October 30, 2014, Thursday
    • Speaker: Xu, Jin (Assistant Professor, Huazhong University of Science and Technology)
    • Topic: Enriching Multi-round Tournament Theory
    • Time: 15:30–17:00
    • Venus: B249
    • Chair: Sun, Xiang
    • Abstract: Empirical organization research has documented convex wage structures for hierarchical firms. We investigate two realistic extensions to Rosen (1986)’s multi-round promotion tournament model, which may separately generate convex wage structures. The first extension, the number of workers competing rises with the hierarchical level, can lead to a convex wage structure. The second extension, the returns of effort increase with the hierarchical level, cannot generate a convex wage structure unless we add further assumptions concerning the production uncertainty and the cost function of effort.
  • October 17, 2014, Friday
    • Speaker: Gong, Qiang (Professor, Southwestern University of Finance and Economics)
    • Topic: 技术创新、股权融资与金融结构转型
    • Time: 10:00–11:30
    • Venue: B127
    • Abstract: 金融体系能否有效支持技术创新,是中国经济转型与产业升级的关键。本文分析了银行贷款和股权融资支持技术创新的不同机制。为技术创新型企业融资存在两种风险:企业的信用风险和创新的不确定性。银行通过资产抵押、违约清算等监管,能够有效克服信用风险,但对于缺乏抵押且不确定性较高的创新企业,银行贷款的回报与承担的风险不相匹配,导致银行缺少激励为创新企业融资。而股权融资中,创新企业能够以新技术新产品的潜在高额回报吸引投资者,企业创新的资金需求和投资者追求高回报、承担高风险的激励相一致,创新企业通过股权融资往往更易获得资金。然而,股权融资的长期性和资金使用的信息不对称,为不法企业攫取股东利益提供了可能,优质的创新企业只有在严格的法律和金融监管制度下,才能获得投资者的充分信任,企业对股权融资的需求才能得到充分满足。本文表明,依靠当前我国银行主导的金融结构,技术创新较难得到有效的金融支持;而发挥股权融资市场对技术创新的重要作用,必须为投资者保护提供优良的制度环境。研究进一步发现,政府对技术创新进行金融扶持时,直接为企业提供研发资助,比为金融机构提供风险投资担保更具效率。
  • September 29, 2014, Monday
    • Speaker: Li, Mengling (PhD candidate, Nanyang Technology University)
    • Topic: Two-sided many-to-many matching with ties
    • Time: 10:00–11:30
    • Venue: B127
    • Chair: Wei, Lijia
    • Abstract: This paper studies a generalized many-to-many matching problem with ties. When ties are allowed in preferences, a stable outcome needs not be Pareto efficient, resulting in efficiency loss. In such problems, a natural solution concept is Pareto stability, which ensures both stability and Pareto efficiency. Our main technical contribution is a polynomial-time algorithm that computes a Pareto stable many-to-many matching in the presence of ties. For a less generalized problem with homogenous preferences on one side of the market, for example, course allocation with ties, we propose two new competing Pareto stable mechanisms known as Pareto-improving draft and dictatorship mechanisms. Using actual data, our simulations show that both mechanisms can significantly improve overall efficiency and welfare of students when compared with the existing mechanism. Besides, the draft mechanism outperforms the dictatorship mechanism despite its non-strategy proof for the students.
  • April 17, 2014
    • Speaker: Sun, Ning (Professor, Shanghai University of Finance and Economics)
    • Title: Hybrid mechanisms for car licenses allocation with budget constraints
    • Time: 09:30–11:00
    • Venue: B127
    • Chair: Wei, Lijia
    • Abstract: In this paper, we use a multi-unit auction model to describe the car licenses allocation problem in China, where buyers are assumed to be of unit demand and hold budget constraints. When designing a car licenses allocation mechanism, the social planner is assumed to consider three factors: efficiency, revenue, and equality. We give a modified Gini coefficient to measure the equality of an allocation mechanism. We then propose a kind of Hybrid Mechanisms for car licenses allocation incorporating auction and lottery, and discuss bidders’ relative strategies. By numerically computing the expressions of efficiency, equality and revenue under the assumption of continuum-mass agents and licenses, we present the performance of the hybrid mechanism with different parameters. Simulations under the assumption of discrete number of agents and licenses are also run to check the robustness of the results of continuum-mass cases. We further describe the Probabilistic Allocation Mechanism and Auctions with price ceilings and compare them with the Hybrid Mechanisms.