Equilibria in vector lattices without ordered preferences or uniform properness

This paper extends a result by Mas-Colell and Richard (Journal of Economic Theory, 1991, 53, 1–11) on the existence of an equilibrium for exchange economies over a vector lattice to cover non-ordered preferences. Moreover, it is shown that the uniformity requirement in the properness assumption made by these authors can be weakened. Furthermore, it is shown that, as a consequence of properness, an equilibrium allocation which is supported by a discontinuous prices can also be supported by continuous prices.     

Quasi-equilibrium in abstract economies without ordered preferences

A definition and an existence proof for quasi-equilibrium in abstract economies is presented When applied to a standard economy this definition coincides with the regular notion of a quasi-equilibrium given by Debreu.     

Equilibrium in abstract economies without ordered preferences

We extend a theorem of G. Debreu on the existence of equilibrium in a generalized N-person game (‘A Social Equilibrium Existence Theorem’). Applying standard techniques the result can be used to prove the existence of equilibrium in economies with interdependent preferences, price-dependent preferences and preferences which may be both non-transitive and non-complete. This generalizes a recent theorem of A. Mas-Colell.     

Equilibrium in economies without ordered preferences or free disposal

Recent work in competitive equilibrium analysis, pioneered by Mas-Colell (1974), ‘An equil- brium existence theorem without complete or transitive preferences’, has established existence of equilibrium in an economy in which preferences are not orderings. The purpose of this note is to show that the assumption of free disposal is not necessary for existence.     

Equilibria in large economies with a separable Banach commodity space and non-ordered preferences

The purpose of this paper is to provide an existence result of equilibria for economies with a measure space of agents, a non-trivial production sector and an infinite dimensional commodity space. The commodity space is modeled by an ordered separable Banach space whose positive cone has a non-empty interior. The discretization approach proposed in this paper, allows us to extend the existence results in Khan and Yannelis [Equilibrium in markets with a continuum of agents and commodities. In: Khan, M.A., Yannelis, N.C. (Eds.), Equilibrium Theory in Infinite Dimensional Spaces. Springer, Berlin, 1991] and Podczeck [Economic Theory 9 (1997) 585] to economies with a non-trivial production sector and with possibly non-ordered but convex preferences as well as partially ordered (possibly incomplete) but non-convex preferences.     

On core-Walras equivalence in Banach lattices

The core-Walras equivalence problem is considered in the commodity space setting of Banach lattices. In particular, necessary and sufficient conditions on the commodity space in order for core-Walras equivalence to hold are established.     

Equilibrium in abstract economies without ordered preferences and with a measure space of agents

We report a generalization of Aumann's (1966) existence theorem to economies without ordered preferences and with externalities in consumption. Our work can alternatively be viewed as a generalization of the Shafer–Sonnenschein (1975) theorem to economies with a continuum of agents.     

Existence of smooth utilities on Banach lattices

In this paper, we focus our attention on the representability of a preference relation by differentiable utility functions when the consumption sets belong to an infinite dimensional commodity space. We obtain sufficient conditions for the existence of a C^r function representing a preference relation defined on an open subset of a Banach lattice.     

Equilibria without the survival assumption

It is well known that an equilibrium in the Arrow–Debreu model may fail to exist if a very restrictive condition called the survival assumption is not satisfied. We study two approaches that allow for the relaxation of this condition. Danilov and Sotskov [Danilov, V.I., Sotskov, A.I., 1990. A generalized economic equilibrium. Journal of Mathematical Economics 19, 341–356], and Florig [Florig, M., 2001. Hierarchic competitive equilibria. Journal of Mathematical Economics 35, 515–546] developed a concept of a generalized equilibrium based on a notion of hierarchic prices. Marakulin [Marakulin, V., 1988. An equilibrium with nonstandard prices and its properties in mathematical models of economy. Discussion Paper No. 18. Institute of Mathematics, Siberian Branch of the USSR Academy of Sciences, Novosibirsk, 51 pp. (in Russian); Marakulin, V., 1990. Equilibrium with nonstandard prices in exchange economies. In: Quandt, R., Triska, D. (Eds.), Optimal Decisions in Market and Planned Economies. Westview Press, London, pp. 268–282] proposed a concept of an equilibrium with non-standard prices. In this paper, we establish the equivalence between non-standard and hierarchic equilibria. Furthermore, we show that for any specified system of dividends the set of such equilibria is generically finite. As a consequence, we have generic finiteness of Mas-Colell’s equilibria with slack, uniform dividend equilibria, and other special cases of our concept.     

A remark on the existence of equilibria in markets without ordered preferences and with a Riesz space of commodities

We show the existence of competitive equilibria in economies without ordered preferences and a Hausdorff locally convex solid Riesz space of commodities. Our principal assumptions are that the commodity space has a predual and that its positive cone has a non-empty interior.     

Rank-dependent preferences without ranking axioms

A key feature of the rank-dependent model for decision making under risk is that the weighting of an outcome depends on its relative rank. This theory received numerous axiomatizations, however, all these sets of axioms need to make an explicit reference to the ranking of the outcomes. This situation is unsatisfactory, as it seems to be desirable to get the ranking property of this model as a consequence of the model, rather than as an assumption. [Yaari, M.E., 1987. The dual theory of choice under risk. Econometrica 55, 95–115] offered a special version of this model (called dual theory), where the utility function is linear. This paper offers a set of axioms implying Yaari’s dual theory without making any reference to the order of the outcomes. The main axiom is called semi betweenness, which, unlike the usual case, is made on random variables rather than on distribution functions.     

Existence of equilibria with infinitely many commodities: Banach lattices reconsidered

The purpose of this paper is twofold. The first aim is to present an extension of the results on the existence of Walrasian equilibrium to the infinite dimensional setting. The result depends on two crucial assumptions. These are the compactness of the collection of feasible allocations and the non-emptiness of the interior of the production set. The proof is a direct generalization of Bewley's (1972) proof for the L_∞ case. The second purpose of this paper is to show that the recent result of Mas-Colell (1986) on the existence of equilibrium for exchange economies on Banach lattices can be obtained through an argument based on the result outlined above. That is, exchange economies on Banach lattices with ‘uniformly proper’ preferences behave as though they were production economies in which the production sets have non-empty interior.     

Equilibria in a large production economy with an infinite dimensional commodity space and price dependent preferences

We prove the existence of a competitive equilibrium in a production economy with infinitely many commodities and a measure space of agents whose preferences are price dependent. We employ a saturated measure space for the set of agents and apply recent results for an infinite dimensional separable Banach space such as Lyapunov’s convexity theorem and an exact Fatou’s lemma to obtain the result.     

An equilibrium existence theorem without complete or transitive preferences

The Walrasian equilibrium existence theorem is reproved without the assumptions of complete of transitive preferences.     

Exclusionary Equilibria in Health-Care Markets

We have demonstrated that when providers of health insurance are perceived to be differentiated by consumers, circumstances may arise under which they find it advantageous to restrict the set of health-care providers that they approve to their customers. Even if all health-care providers are equally qualified and efficient, payers may choose to contract with a selected subset of them in order to secure more favorable contract terms. Moreover, in a concentrated health-care market that consists of two health insurance companies (payers) and two health-care providers (hospitals), both payers may choose to contract with only one of the hospitals while excluding the other completely from the market. When consumers' valuation of an extended choice of providers is small in comparison with the extent of differentiation that exists between the payers, such an exclusionary outcome is the unique equilibrium of the game.     

Equilibria in a class of aggregative location games

Consider a multimarket oligopoly, where firms have a single license that allows them to supply exactly one market out of a given set of markets. How does the restriction to supply only one market influence the existence of equilibria in the game? To answer this question, we study a general class of aggregative location games where a strategy of a player is to choose simultaneously both a location out of a finite set and a non-negative quantity out of a compact interval. The utility of each player is assumed to depend solely on the chosen location, the chosen quantity, and the aggregated quantity of all other players on the chosen location. We show that each game in this class possesses a pure Nash equilibrium whenever the players’ utility functions satisfy the assumptions negative externality, decreasing marginal utility, continuity, and Location–Symmetry. We also provide examples exhibiting that, if one of the assumptions is violated, a pure Nash equilibrium may fail to exist.     

中国经济周期特征与太阳黑子均衡

本文在Benhabib、Farmer（1994）、Farmar、Guo（1994,1995）的不确定性均衡模型框架上,构建了一个考虑了信念偏差所代表的不确定因素和政府支出冲击的太阳黑子RBC模型来解释宏观经济的周期波动;并利用中国改革开放以来的经济数据,对该模型进行了实证检验。我们发现,该模型能够解释80%以上的中国经济波动特征;可以合理预测各宏观经济变量与产出之间的协动关系,合理预测各变量与劳动生产率之间的相关关系;对中国经济的解释力远远高于标准RBC模型,说明这一模型比较适合解释中国经济波动。另外,还发现信念冲击与政府支出冲击均是中国宏观经济波动的重要冲击来源,分别可以解释约30%、60%的经济波动,表明二者均是中国经济波动不可忽略的重要影响因素。我们的发现从不确定均衡和财政政策变动角度对宏观经济波动(比如,消费、就业、投资)的一些现象提供了合理解释。