Equilibrium theory under ambiguity

We extend the classical results on the Walras–core existence and equivalence to an ambiguous asymmetric information economy; that is, an economy where agents maximize Maximin Expected Utility (MEU). The interest of considering ambiguity arises from the fact that, in the presence of MEU decision making, there is no conflict between efficiency and incentive compatibility (contrary to the Bayesian decision making). Our new modeling of an ambiguous asymmetric information economy necessitates new equilibrium notions, which are always efficient and incentive compatible.     

Existence of an equilibrium for infinite horizon economies with and without complete information

This work proves the existence of an equilibrium for an infinite horizon economy where trade takes place sequentially over time. There exist two types of agents: the first correctly anticipates all future contingent endogenous variables with complete information as in Radner [Radner, R. (1972). Existence of equilibrium of plans, prices and price expectations in a sequence of markets. Econometrica, 289–303] and the second has exogenous expectations about the future environment as in Grandmont [Grandmont, J. M. (1977). Temporary general equilibrium theory. Econometrica, 535–572] and information based on the current and past aggregate variables including those which are private knowledge. Agents with exogenous expectations may have inconsistent optimal plans but have predictive beliefs in the context of Blackwell and Dubbins [Blackwell, D., Dubins, L. (1962). Merging of opinions with increasing information. The Annals of Mathematical Statistics, 882–886] with probability transition rules based on all observed variables. We provide examples of this framework applied to models of differential information and environments exhibiting results of market selection and convergence of an equilibrium. The existence result can be used to conclude that, by adding the continuity assumption on the probability transition rules, we obtain the existence of an equilibrium for some models of differential information and incomplete markets.     

Robust implementation under alternative information structures

In this paper we consider a model in which agents have complete information about their neighbors and, possibly, incomplete information about the rest of the environment. We consider two different informational frameworks. In the first, agents do not have priors about the relevant characteristics in the rest of the environment. In the second, agents are supposed to have priors about the unknown characteristics. We present a mechanism which implements any social choice correspondence satisfying monotonicity and no veto power in both informational settings for every possible prior thus requiring little knowledge from the point of view of the designer of the information possessed by agents about the environment. The authors wish to thank J. Canals, B. Chakravorty, P. Chander, C. Herrero, G. Orosel, D. Schmeidler, W. Thomson, W. Trockel, F. Vega, A. Villar, T. Yamato and two anonymous referees for helpful comments. The usual disclaimer applies. The first author acknowledges financial support from the Institució Valenciana d’Estudies i Investigació; L.V.I.E. and DGICYT under projects PB/88-0289 and PB/91-0756. The second author acknowledges financial support from DGICYT under project PB/90-0156. A previous version of the paper was written when authors visited (May 1991) the Institute of Mathematical Economics (Bielefeld) to which authors are grateful.     

PRIVATIZATION AND EFFICIENCY: FROM PRINCIPALS AND AGENTS TO POLITICAL ECONOMY

Abstract.  We survey the theoretical literature on privatization and efficiency by tracing its evolution from the applications of agency theory to recent contributions in the field of political economy. The former extend the theory of regulation with incomplete information to address privatization issues, comparing state-owned enterprises with private regulated firms. The benefits of privatization may derive either from the constraints it places on malevolent agents or from the impossibility of commitment by a benevolent government because of incomplete contracts. Contributions dealing with political economy issues separate privatization from restructuring decisions. They either explore bargaining between managers and politicians or analyse the impact of privatization shaped by political preferences on efficiency. The theoretical results regarding the relation between privatization and efficiency do not lead to any definitive conclusion. Privatization may increase productive efficiency when restructuring takes place whereas its effects on allocative efficiency still remain uncertain.     

基于可持续发展观下的环境会计信息披露

科学技术的日新月异使全球经济正以前所未有的速度向前发展,为人类创造了大量的财富。但经济快速增长的同时,随之而来的是自然资源的迅速耗竭和环境的严重污染。环境问题已由局部问题上升为人类生存性问题。要真正的让全社会认识到企业对环境的影响程度,必须加强企业对环境造成损害程度科学的披露,这就涉及到环境会计信息披露相关问题。文章从可持续发展观的视角入手,阐述了目前我国环境信息披露的现状和方式以及环境信息披露的局限性,并就目前的局限性提出了改进建议。     

Efficiency and information aggregation in auctions with costly information

Consider an auction in which k identical objects are sold to n > k bidders who each have a value for one object which can have both private and common components to it. Private information concerning the common component of the object is not exogenously given, but rather endogenous and bidders face a cost to becoming informed. If the cost of information is not prohibitively high, then the equilibrium price in a uniform price auction will not aggregate private information, in contrast to the costless information case. Moreover, for a wide class of auctions if the cost of information is not prohibitively high then the objects can only be allocated in a weakly efficient sense, and then only if the equilibrium proportion of endogenously informed agents is vanishing as the economy grows. In spite of these results, it is shown that there is a mechanism for which there exist equilibria and for which (weak) efficiency is achieved as the economy grows in the face of endogenous information acquisition.Received: 6 August 2001, Accepted: 27 July 2002, JEL Classification: C72, D44, D82Financial support under NSF grant SBR-9507912 is gratefully acknowledged. I thank Valentina Bali for conversations out of which this project grew, and Larry Ausubel for a very helpful discussion of an early version of this paper at the 1998 summer meetings of the Econometric Society from which I have borrowed in structuring the exposition of the paper. I also thank Andy Postlewaite, Jeroen Swinkels, and an associate editor and anonymous referee for helpful comments and suggestions on earlier drafts.     

会计信息失真的原因探析

会计信息失真问题严重干扰我国国民经济正常运行。针对不同类别的会计信息失真探析其形成的原因。     

Rational expectations equilibrium and the strategic choice of costly information

This paper studies costly information acquisition in one-good production economies when agents acquire private information and prices transmit information. Before asset markets open, agents choose the quality of their private information. After this information stage, agents trade assets in sequentially complete markets taking into account their private information and the information revealed by equilibrium prices (rational expectations equilibrium, (Radner, R., 1979. Rational expectations equilibrium: generic existence and the information revealed by prices, Econometrica 47, 655–678.)). An overall equilibrium in asset and information market is defined as a Nash equilibrium of the information game in which agents’ actions are information choices and their utility payoffs are the ex-ante expected utilities of the corresponding rationale expectations equilibrium. This paper shows that for a generic set of economies parameterized by endowments and productivity shocks, an overall equilibrium in information and asset market (a Nash equilibrium of the induced information game) with costly information acquisition and fully-revealing prices exists. In other words, informational efficiency is in general consistent with costly information acquisition.     

On the structure of the set of fixed price equilibria

Working in the framework suggested by Drèze, this paper studies the number of fixed price equilibria and their continuity with respect to the price system. In an exchange economy, the concept of a rationing scheme is introduced, which specifies how shortages are shared among agents. For given utility functions and a given rationing scheme, under standard assumptions, an existence theorem is recalled, and it is shown that the graph of the equilibrium correspondence, when prices and initial endowments vary, is a piecewise continuously differentiable manifold. Moreover, generically, the number of equilibria for an economy, at given prices, is finite and the set of equilibria varies continuously with the price system and the initial endowments.     

Preferences and information processing under vague information

The standard decision-theoretic model separates information and preferences. We argue that some behavioral phenomena in information processing (e.g., polarization) are closely related to this separation.We propose a model in which agents receive vague information, which they refine when they are required to make probabilistic judgments, or to take an action. By doing so, they also refine their beliefs about some traits or states (e.g., their information-processing ability), which affects their utility.     

Equilibrium with coordination

The obvious equilibrium concepts in the simplest institutions for transferring ownership of commodities—bilateral exchange—are neither Nash equilibria nor cooperative equilibria. To study such equilibria as special cases of equilibria of a social system it is necessary to introduce coordination. Two or more agents coordinate their actions, if, when they consider an alternative to a state, they take as given—for agents with whom they coordinate—the alternative state. If there is no coordination we obtain Nash equilibrium as a special case. If there is complete coordination we obtain optimality as a special case. The main result is an existence theorem for a social system with coordination. This theorem is then applied to prove existence of exchange equilibria in an economy with bilateral exchange.     

区域性公共物流信息平台的构建路径分析

在调研、分析经济区域内的物流发展和信息化,各经济主体的功能需求,明确建设目标和任务的基础上,设计各子系统平台,采用一定的技术方法进行系统集成,并构建起系统安全运行机制,从而建设一个高效、敏捷的区域性公共物流信息平台。     

Inflation and output volatility under asymmetric incomplete information

The assumption of asymmetric and incomplete information in a standard New Keynesian model creates strong incentives for monetary policy transparency. We assume that the central bank has better information about its objectives than the private sector, and that the private sector has better information about shocks than the central bank. Transparency has the potential to trigger a virtuous circle in which all agents find it easier to make inferences and the economy is better stabilised. Our analysis improves upon existing work by endogenising the volatility of both output and inflation. Improved transparency most likely manifests itself in falling output volatility.     

企业会计信息失真成因及对策

会计信息真实与否,对整个国民经济的健康运行是至关重要的。小至一个单位,大到整个国家,真实的会计信息是经济健康并协调发展的基础,目前我们远未能从总体上遏制虚假信息的蔓延,为确保正确决策,会计信息必须具有相关性和可靠性的质量保证。     

Learning and coordination with dispersed information

We analyse adaptive learning in a model of incomplete and dispersed information, with externalities and strategic interactions. We build on the framework proposed by Angeletos and Pavan (2007a) and extend it to a dynamic multi-period setting where agents need to learn to coordinate. We derive conditions under which adaptive learning obtains in such setting and show that, when actions are strategic substitutes, the information structure affects the speed of convergence: while more precise private information is beneficial, better public information has negative effects. We also show that adaptive learning dynamics converge to the Bayesian Nash equilibrium, which means that agents can learn to act strategically by relying only on observable (exogenous) information.     

上市公司信息披露违规情况分析

上市公司信息披露的真实可靠是构筑证券市场的基石。本文通过对我国上市公司信息披露违规行为以及有关部门对违规行为处罚情况的调查研究,分析了上市公司信息披露违规行为产生的原因,并提出应从内外两方面加强对上市公司信息披露的监督,以避免信息披露违规行为的发生。     

价值工程理论下的会计信息价值研究

经济越发展会计越重要,是基于会计信息在经济中所起的作用而言的,可见人们对会计信息作用的认识是很深的,但对其价值研究很少,本文运用价值工程理论对会计信息进行价值分析,试图找到会计信息的功能,通过完善和增加其功能,降低成本,提高会计信息价值,更好地为现代经济服务和人类服务。     

Portfolio constraints,differences in beliefs and bubbles

I propose an arbitrage-based theory of bubbles in economies with general portfolio constraints and differences in beliefs. I find that, in general, bubbles cannot exist unless the constraints restrict the demand for credit sufficiently to induce low interest rates. Speculation due to heterogeneous beliefs does not cause bubbles. Ruling out bubbles under asymmetric information requires stronger assumptions: the presence of some uninformed agents and mild portfolio restrictions (debt or borrowing constraints), or alternatively, the existence of some impatient and fully informed agents.     

构建中小物流企业公共信息平台的探讨

当今时代是知识经济时代,更是信息技术时代,在这个时代物流已经成为企业越来越重视的第三方利润源泉,我们的物流公司增长速度迅猛．同样物流业的竞争也日趋激烈。在角逐日常激烈的竞争要立于不败之地,信息共享,满仓,满载是降低成本的最佳方式．但如果做到这样信息的开放性和共享变得尤重要：我国物流企业中绝大多数都是中小企业,资金与技术实力都相对薄弱．这就给即想发展信息化又无法过多投入的中小物流企业来说,构建一个公共信息平台显得特别重要。     

Existence of equilibria in atomless production economies with price dependent preferences

The existence of a competitive equilibrium for an economy with a measure space of agents is proved by reducing the economy to a three-person game and then applying Debreu's lemma (1952). In addition to the relative simplicity and shortness of the proof, we generalize known results [Aumann (1966), Hildenbrand (1970), Schmeidler (1969)] by allowing both price dependent preferences and satiation.