Efficient markets and Bayes’ rule

Summary. A series of financial anomalies motivated the development of new theories that modify the rational expectations ideal. Two possibilities have been systematically explored. The literature on behavioral finance relaxes the assumption that agents form beliefs according to the laws of probability and assume, instead, that simpler heuristic rules are used. Another stream of the literature assumes that agents process information according to Bayes rule, but do not posses sufficient information to know the true data generating process. In this paper, Bayesian and Behavioral agents coexist and trade in a standard dynamic asset pricing model. A long-standing conjecture is demonstrated. It is shown that, under suitable assumptions, Bayesian agents drive Behavioral, non-Bayesian agents out of the market. Hence, asset prices are eventually determined under the Bayesian paradigm.Received: 3 June 2004, Revised: 17 September 2004, JEL Classification Numbers: D83.Preliminary versions have circulated under the titles Markets Favor Bayesian Models and Market Selection of Empirical Models under Limited Information. I thank Larry Blume, David Easley, Larry Epstein, Armando Gomes, Bruce Hansen, Lars Hansen, Richard Kihlstrom, Grace Koo, George Mailath, Werner Ploberger, Andrew Postlewaite and Shakeeb Khan for useful comments. I also thank participants at the NBER GE meetings, Evolutionary Finance conference in Zurich, Latin American Meetings of the Econometric Society, Stanford Institute for Theoretical Economics, the Instituto de Matematica Pura e Aplicada, the theory seminar at Brown, Chicago, Harvard-MIT, Minnesota, Penn and Wisconsin. I gratefully acknowledge the financial support from the National Science Foundation Grant SES 0109650.     

Bargaining Outcomes with Double-Offer Arbitration

Increasingly, arbitration is becoming used to resolve bargaining disputes in a variety of settings. Reducing dispute rates is often listed as a main goal in designing arbitration mechanisms. Conventional arbitration and final-offer arbitration are two commonly used procedures, but theoretical examinations of these arbitration procedures show that disputants’ final bargaining positions do not converge and disagreement is likely. This article contains results from a set of experiments designed to compare bargaining outcomes under the two commonly used arbitration procedures with outcomes under an innovative procedure called “double-offer” arbitration (Zeng et al., 1996). This procedure requires that disputants make two final offers at impasse: a primary and a secondary offer. The arbitrator evaluates the pairs of offers using a linear criterion function, and theory suggests the secondary offers converge to the median of the arbitrator’s preferred settlement distribution. Because the procedure’s rules are that convergence of offers generates a settlement at those offers, this theoretical convergence result implies that arbitration is not needed in the end. Experimental results indicate that dispute rates in double-offer arbitration are, on average, about the same as dispute rates in conventional arbitration. However, other results show reason to favor double-offer arbitration. Specifically, in repeated bargaining, there is concern over whether use of an arbitration procedure becomes addictive and makes bargainers more likely to use the procedure in the future-a “narcotic effect.” The data show that double-offer arbitration is non-addictive, whereas both conventional and final-offer arbitration are.     

我国资本市场分形特性研究

任何科学发展,包括社会科学在内,其前沿问题都是非线性问题.但是,由于现行线性模型的简单易行,实际中仍被广泛运用.随着经济行为越来越复杂,只有用动态的非线性模型刻画某些经济现象,才能较好地反映客观现实.近二十年来,作为研究非线性问题科学分支之一的分形理论,也就成了经济学科研究与应用的前沿领域.本文探讨了分形时间序列的基本特点及Hurst指数计算方法,描述了计算时间序列Hurst指数的一般方法,运用R/S分析法分析了我国资本市场的分形特性,通过实例分析,总结了资本市场分形理论的基本内容.     

Endogenous structural change and crisis in a multiple time-scales growth model

The slow and endogenous twist of economic macro-structure makes up an important evolutionary feature of capitalist economies, and may be at the root of structural crisis. In this line, a Goodwinian growth model with increasing returns and profit-sharing that tries to picture a simple scenario of the seventies crisis is considered. It is shown that the exhaustion of the Kaldor-Verdoorn “productivity law” can entail, in a nonlinear framework, a “catastrophic” bifurcation from a “high” to a “low” growth path. Slow/fast dynamical systems then allow one to formalize a multiple time-scales dynamics where the growth path is shaped by the structural framework in which it takes place, but has also a long -un feedback. Structural change and crisis appear as long term and endogenous outcomes.     

面向电子商务的现代物流管理信息系统的开发

结合现代物流技术发展趋势，分析探讨了面向电子商务的现代物流管理信息系统的开发技术路线，关键技术内容，功能体系结构设计及分层逻辑模型设计。     

我国建筑业全生命周期价值链的应用研究

长期以来,我国建筑业缺乏对全生命周期价值链管理的整体关注,价值链中各个环节相互脱节,没有共同的价值目标,导致了成本较高的现状。本文旨在通过对建筑业全生命周期价值链的分析,拓展我国建筑业成本管理的关注面。并通过工程总承包模式对现有价值链进行优化,把勘察、设计、施工归集在同一个主体下管理,提高用户对建筑产品的满意度,降低产品成本。     

银行信用证议付及其追索权的法学解读

在法学视角下，信用证议付实质上是议付银行向信用证受益人（出口商）给付价值后买入信用证项下的汇票和整套单据的法律行为。议付不同于出口押汇。议付是一种买卖汇票和单据的行为，而出口押汇是一种以单据为质押的融资行为。议付单据遭到开证银行拒付，议付银行有权对信用证受益人（出口商）行使追索权。议付银行的这种追索权既可以来自于合同条款的约定，也可以来自于票据法所赋予的请求权。     

股票市场收益率波动长记忆性的分解及实证研究

目前股票市场长记忆性检验和建模方法，不能很好地消除短期记忆的影响，针对这一问题，本文提出寻找序列的突变点，通过将序列分解为只包含长记忆性部分和不包含长记忆性部分的序列分解技术，来排除短期记忆的影响。对上证指数和深圳成分指数收益率波动的长记忆性进行实证研究发现，将序列分解以后进行长记忆性检验，不仅可以得出长记忆性检验更为精确的结论，同时可以检验序列分解过程的效果。     

中国股票市场市盈率的检验分析

市盈率高低是我国股市的关注焦点之一。本文在比较国外证券市场的市盈率之后认为我国的市盈率偏高。这种推测得到我们理论研究和模型结论的支持,我国股市市盈率由于系统风险的掩藏、股票初始发行价偏高和股市投机性等因素而呈现较高的倍数。从2004年我国股市市盈率开始下降,逐渐接近我们模型的估计值。此外,我们实证分析认为,市盈率的高低与GDP增长、股票收益波动和国有股比重等因素不存在严格的变动关系,市盈率呈现出一种随机游走的态势,市盈率不是稳定的区间值,而是一系列的动态的时间序列变量值。     

可转换债券市场价格与其基准股票市盈率关系初探

本文试图探讨可转换债券市场价格与其基准股票市盈率间的关系。从理论上分析,市盈率作为一个较易获得的市场指标,包含了上市公司增长机会(growth opportunity)的信息,反映了投资者对未来股价上升的预期。同时可转换债券的价格对其基准股票价格未来上升的可能性十分敏感,因此市盈率与可转换债券市场价格间应存在一定关系。但根据对上海证券交易所转债的实证分析得到:目前我国转债的市场价格与其基准股票市盈率间的关系并不显著,因而市盈率指标不能作为判断转债投资价值的有效依据。