Refinements and incentive efficiency in Walrasian models of insurance economies

The literature on Walrasian markets in large economies with adverse selection has used various equilibrium refinements, but has obtained no general incentive efficiency of equilibrium, namely when cross-subsidies are needed for efficiency. We show that the same refined equilibria may also be incentive inefficient even when general mechanisms that allow for such cross-subsidies are priced and can be traded. In the process, we also prove existence of some type of forward induction equilibria in this context.     

Representation of non-transferable utility games by coalition production economies

We prove that every compactly generated non-transferable utility (NTU) game can be generated by a coalition production economy. The set of Walrasian payoff vectors for our induced coalition production economy coincides with the inner core of the balanced cover of the original game. This equivalence depends heavily on our representation. We exemplify that this equivalence need not hold in other representations. We also give a sufficient condition for the existence of a Walrasian equilibrium for our induced coalition production economy.     

Non-manipulability in Walrasian cost games

JEL classification: D41, D51 Received: 24 December 1999 / Accepted: 18 October 2001     

The veto mechanism in atomic differential information economies

We establish new characterizations of Walrasian expectations equilibria based on the veto mechanism in the framework of differential information economies with a complete finite measure space of agents. We show that it is enough to consider the veto power of a single coalition, consisting of the entire set of agents, to obtain the Aubin private core. Moreover, we investigate on the veto power of arbitrarily small and big coalitions, providing an extension to mixed markets of well known Schmeidler (1972) and Vind’s (1972) results in terms of Aubin private core allocations.     

On the Edgeworth conjecture for production economies with public goods: A contract-based approach

The paper applies and elaborates a contractual approach to study economies with a production of public goods. The barter contractual approach was developed in  and  for exchange economies; it is now modified and extended to the production economy. This includes hereby the introduction of a production contract and the adoption of known earlier notions: a web of contracts, coalitional domination for webs, a partial breaking of contracts, and so on. Thus specific notions of properly contractual and fuzzy contractual allocations for an economy with public goods are introduced and their equivalence with Lindahl equilibria is stated. These theorems can be interpreted as a new way of perfect competition presentation.     

Representation of transferable utility games by coalition production economies

We prove that, by the method of construction of a coalition production economy due to Sun et al. [Sun, N., Trockel, W., Yang, Z., 2008. Competitive outcomes and endogenous coalition formation in an n$n$-person game. Journal of Mathematical Economics 44, 853–860], every transferable utility (TU) game can be generated by a coalition production economy. Namely, for every TU game, we can construct a coalition production economy that generates the given game. We briefly discuss the relationship between the core of a given TU game and the set of Walrasian payoff vectors for the induced coalition production economy.     

Equilibrium in a market with intermediation is Walrasian

We show that a profit maximizing monopolistic intermediary may behave approximately like a Walrasian auctioneer by setting bid and ask prices nearly equal to Walrasian equilibrium prices. In our model agents choose to trade either through the intermediary or privately. Buyers (sellers) trading through the intermediary potentially trade immediately at the ask (bid) price, but sacrifice the spread as gains. A buyer or seller who trades privately shares all the gains to trade with this trading partner, but risks costly delay in finding a partner. We show that as the cost of delay vanishes, the equilibrium bid and ask prices converge to the Walrasian equilibrium prices. Received: 2 February 1996 / Accepted: 28 March 1997     

Robust efficiency in mixed economies with asymmetric information

In this paper, we study robustly efficient allocations in a pure exchange economy. Answering a question of Hervés-Beloso and Moreno-García (2008), we present an extension of their main result to an asymmetric information mixed economy whose commodity space is an ordered separable Banach space having an interior point in its positive cone.     

A decentralized and informationally efficient mechanism realizing fair outcomes in economies with public goods

We present a decentralized mechanism (called Lindahl Egalitarian), which yields Pareto efficient and envy free allocations (i.e. fair outcomes). We show that the mechanism is informationally efficient in general production economies with an arbitrary, but finite, number of private and public goods, and a finite number of agents. The mechanism reduces to the Walrasian mechanism starting from equal wealth when no agent cares about public goods. We also prove that the set of Public Competitive equilibrium allocations (from equal endowments and proportional taxation), and the set of the Lindahl Egalitarian equilibrium allocations are the same. We are grateful to Xavier Calsamiglia and Albert Marcet for helpful conversations, and to A. de la Fuente, I. Macho, and an anonimous referee for useful suggestions. A. Manresa’s research has been supported by the grant CICYT PB90-0172. J. Aizpurua acknowledges financial support from the Government of Navarra.     

Arbitrage and equilibrium in unbounded exchange economies with satiation

In his seminal paper on arbitrage and competitive equilibrium in unbounded exchange economies, Werner (1987) proved the existence of a competitive equilibrium, under a price no-arbitrage condition, without assuming either local or global nonsatiation. Werner’s existence result contrasts sharply with classical existence results for bounded exchange economies which require, at minimum, global nonsatiation at rational allocations. Why do unbounded exchange economies admit existence without local or global nonsatiation? This question is the focus of our paper. First, we show that in unbounded exchange economies, even if some agents’ preferences are satiated, the absence of arbitrage is sufficient for the existence of competitive equilibria, as long as each agent who is satiated has a nonempty set of useful net trades– that is, as long as agents’ preferences satisfy weak nonsatiation. Second, we provide a new approach to proving existence in unbounded exchange economies. The key step in our new approach is to transform the original economy to an economy satisfying global nonsatiation such that all equilibria of the transformed economy are equilibria of the original economy. What our approach makes clear is that it is precisely the condition of weak nonsatiation – a condition considerably weaker than local or global nonsatiation – that makes possible this transformation.     

Characterization of an extended Walrasian concept for open economies

The consistency axiom, which is quite prominent in the framework of concepts of cooperative games, can be used to characterize concepts for economies as well. Dagan [Dagan, N., 1996b. Consistency and the Walrasian allocations correspondence. A revised version of Economics Working Paper No. 151, Universitat Pompeu Fabra, Barcelona, Spain.] and van den Nouweland et al. [van den Nouweland, A., Peleg, B., Tijs, S., 1996. Axiomatic characterization of the Walras correspondence for generalized economies. Journal of Mathematical Economics 25, 355–372.] used the setting of open economies to give axiomatic characterizations of an extension of the Walras correspondence. Here, we will characterize the proportional Walrasian concept, an extension which was proposed by Thomson [Thomson, W., 1992. Consistency in exchange economies. Mimeo, Department of Economics, University of Rochester, Rochester, NY.] and which is non-empty on a much bigger class of open economies. Apart from consistency properties and other frequently used axioms, we also employ an axiom on distribution.     

Resource-envy-free and efficient allocations: A new solution for production economies with dedicated factors

I consider the problem of determining an equitable and efficient allocation of resources in production economies with factors which must be dedicated to production and cannot be consumed directly. First, I show that in such economies envy-free and efficient allocations exist under standard assumptions. However, I argue this notion of fairness is unsuitable for the present context. I then introduce a new notion of fairness, which I call resource-envy-freeness. First, I associate with each consumption bundle its resource footprint consisting of the vector of factors used to produce it. I then show that preferences over consumption bundles can be extended to preferences over factor bundles. An allocation is resource-envy-free if no agent prefers another agent’s resource footprint to its own. The analysis of resource-envy-free allocations in production is exactly analogous to the analysis of envy-free allocations in exchange. I establish that resource-envy-free and efficient allocations exist under standard assumptions, and I demonstrate that such allocations are intuitively appealing.     

The equilibrium set of infinite dimensional Walrasian economies and the natural projection

The natural projection plays a fundamental role to understand the behavior of the Walrasian economies. In this paper, we extend this method to analyze the behavior of infinite dimensional economies. We introduce the definition of the social equilibrium set, and we show that there exists a bijection between this set and the Walrasian equilibrium set of an infinite dimensional economy. In order to describe the main topological characteristics of both sets, we analyze the main differential characteristics of the excess utility function and then, we extend the method of the natural projection as suggested by Y. Balasko.     

期货市场操纵的认定：美国经验及其启示

基于美国期货市场的实践和学术界的相关研究,提出了期货市场操纵的定义,归纳了期货市场操纵的类型和手法。通过几个典型判例分析了美国在对期货市场操纵进行认定上的经验,并介绍了国外学术研究在市场操纵的判断依据和方法上的进展。在此基础上,得出了美国经验与国外学术研究对中国期货市场规范发展的启示。     

基于实际活动操控的盈余管理研究——国外文献述评及启示

基于应计利润的盈余管理研究过去一直是盈余管理研究的主流,但实务界日益呈现的证据表明,应计利润操控并非盈余管理的首要方式,管理层在面临实现特定盈余目标的动机、受限的应计利润会计自由裁量权、后安然时代国际上从紧的会计准则、管理审查和股东法律诉讼的风险时,都可能通过实际操控影响现金流从而管理盈余。对实际活动操控的盈余管理行为的探索能够拓展当前有限的盈余管理研究,有助干改善公司治理、提升盈余信息质量,促进证券市场更健康有序地发展。为此,本文首先对国际现有实际活动操控研究相关文献进行了梳理,具体包括实际活动操控方式识别的相关研究、实际活动操控经济后果及投资者反应的相关研究、应计项目操控与实际活动操控关系的相关研究;然后着重分析了实际活动操控手段的四种计量模型,最后总结了当前真实盈余管理研究的主要成果及局限性,为拓展我国的真实盈余管理研究及提高盈余质量提供了方向。     

Cash management economies in the production of food

This study suggests that the behavior of demand of cash by business firms can better be understood by empirical testing theory on data derived from individual units rather than making unrealistic assumptions to justify testing of aggregated data. Using data for firms in the food industry, this study shows that the rate of interest is a significant variable in explaining the demand for cash. Furthermore, the statistical results indicate that the economies of scale in the management of cash depends upon the type of goods produced by the corporations under study. Accordingly, one cannot make any generalization regarding the question of the economies of scale in the management of cash.     

Sequential regularity in smooth production economies

In general equilibrium models where agents trade sequentially in multiple periods, the equilibria that endogenously occur in later periods can be robustly indeterminate if production sets are not everywhere differentiable (as. for example, with linear activities). The present paper proves that if technology is smooth, then equilibria are sequentially regular. That is. the equilibria of the endogenously generated economies occurring in later periods that confirm the unanimous expectations formed by agents in earlier periods are regular (and thus, for example, isolated from other equilibria). The paper also proves and utilizes the standard result that the overall intertemporal equilibria are regular.     

A general equilibrium model with external scale economies in production

A general-equilibrium model of an urban economy is described. The standard residential land use model is extended to include a well-defined production/employment sector. External scale economies occur in the production of the city's export good. The model is designed for the numerical computation of equilibria and optima.