Toward a Strategic Foundation for Rational Expectations Equilibrium

A step toward a strategic foundation for rational expectations equilibrium is taken by considering a double auction with n buyers and m sellers with interdependent values and affiliated private information. If there are sufficiently many buyers and sellers, and their bids are restricted to a sufficiently fine discrete set of prices, then, generically, there is an equilibrium in nondecreasing bidding functions that is arbitrarily close to the unique fully revealing rational expectations equilibrium of the limit market with unrestricted bids and a continuum of agents. In particular, the large double‐auction equilibrium is almost efficient and almost fully aggregates the agents' information.     

Strategic Supply Function Competition With Private Information

A finite number of sellers (n) compete in schedules to supply an elastic demand. The cost of each seller is random, with common and private value components, and the seller receives a private signal about it. A Bayesian supply function equilibrium is characterized: The equilibrium is privately revealing and the incentives to rely on private signals are preserved. Supply functions are steeper with higher correlation among the cost parameters. For high (positive) correlation, supply functions are downward sloping, price is above the Cournot level, and as we approach the common value case, price tends to the collusive level. As correlation becomes maximally negative, we approach the competitive outcome. With positive correlation, private information coupled with strategic behavior induces additional distortionary market power above full information levels. Efficiency can be restored with appropriate subsidy schemes or with a precise enough public signal about the common value component. As the market grows large with the number of sellers, the equilibrium becomes price‐taking, bid shading is on the order of 1/n, and the order of magnitude of welfare losses is 1/n². The results extend to inelastic demand, demand uncertainty, and demand schedule competition. A range of applications in product and financial markets is presented.     

考虑信息不对称的电子市场动态契约设计

近年来,伴随着互联网技术的快速发展以及电子商务在广大消费者中的日益普及,以淘宝网、eBay等为代表的电子市场的销售规模和交易金额都实现了跳跃式的增长。但是,在买卖双方交易数量快速增加的同时,提供交易平台的电子市场所有者始终缺乏有效的收费模式来实现自身的利润最大化,这一窘境已经得到产业界和学术界越来越多的关注。当前,各类电子市场大多采用的收费模式是以每个卖家前一期的销售历史来预测该卖家下一期的销售数量,并以此作为基准来动态更新电子市场对于该卖家下一期的收费标准。这种收费方法暗含的假设是相邻周期间产品销量为强正相关,但忽略了产品销量因季节性、流行性、替代产品威胁等各类因素影响而导致的更加复杂的中长期变化趋势。针对这一问题,本文为电子市场所有者提供了一类新的个性化动态契约机制。这种契约机制假设相邻周期的产品销量服从联合正态分布,在每个周期开始前,卖家能够充分考虑到各类因素的影响,从而对于下一期销量做出比电子市场所有者更准确的条件预期。但是,卖家对于相邻周期销量间的相关系数的观测属于私有信息,为了诱导卖家披露这一私有信息,电子市场所有者在每周期开始前需要根据该卖家上一周期的实际销售数量向卖家提供一系列契约（a menu of contracts）供卖家选择。本文构建了这种个性化动态契约的参数优化问题。求解结果揭示了一个简单的决策准则,即最优的契约参数可以表示为关于上述相关系数的failure rate的函数。通过一组数值试验,本文将这种契约与其他三类契约进行了对比,验证了这种契约能够充分地利用卖家的私有信息来提升电子市场所有者的利润。本文所述的契约机制在互联网环境下具有较强的可操作性,因此可以为电子市场所有者提供直接的管理参考和决策依据。     

电子市场价格分散、信息价值与效率:多视角的分析框架

电子市场是集合买卖双方交换价格和产品信息的跨组织信息系统,已成为撮合交易的重要虚拟场所,其对有形市场的影响力日益彰显,引起理论界和实务界的密切关注.本文将电子市场价格分散、信息价值与效率问题放在同一分析框架下研究,从不同的视角审视电子市场现存文献的解释力度;指出电子市场价格分散现象是多种因素综合作用的结果,消费者的搜寻异质、买方偏好(品牌、信任与忠诚度等因素)、服务质量、市场结构特征等多变量共同决定了电子市场的价格分散度、信息价值及效率大小;最后,提出了未来电子市场的研究方向,即通过价格比较购物技术扩散模型的引入,建立集影响电子市场价格的多变量于一体的理论分析框架,探讨电子市场价格分散及与其相关联的信息价值测度和市场效率等基础理论问题.     

水平竞争条件下的供应链信息泄露策略

本文探讨非对称信息下,制造商针对议价能力不同的大型及小型零售商分别采用了收益共享、批发价合约时,大型零售商的市场信息被制造商泄露给竞争对手,从而对供应链产生的影响。通过对比有无信息泄露下各方成员的博弈过程,分析供应链信息泄露的原理;进而在制造商总是会泄露信息的前提下,构建基于信号传递的信息泄露下供应链成员决策模型,分别讨论分离均衡与混同均衡两种情形下,零售商的订货策略及其相应的收益。在此基础上进一步做出扩展,制造商有主动权以选择是否泄露信息的情况,对比分析零售商的策略选择问题。经过分析发现,出于自身利益的角度,制造商总是会泄露信息,从而导致供应链的整体利润下滑。对此,大型零售商的订货策略选择与市场需求的波动程度有关：波动较小则选择混同均衡;波动较大则选择分离均衡。特别地,当市场需求为低时,大型零售商的最优订货量会向下扭曲,即支付一定的“信息租金”作为应对信息泄露的代价。