Existence of a competitive equilibrium in a one sector growth model with heterogeneous agents and irreversible investment

Summary. We prove existence of a competitive equilibrium in a version of a Ramsey (one sector) model in which agents are heterogeneous and gross investment is constrained to be non negative. We do so by converting the infinite-dimensional fixed point problem stated in terms of prices and commodities into a finite-dimensional Negishi problem involving individual weights in a social value function. This method allows us to obtain detailed results concerning the properties of competitive equilibria. Because of the simplicity of the techniques utilized our approach is amenable to be adapted by practitioners in analogous problems often studied in macroeconomics. Received: September 13, 2001; revised version: December 9, 2002 RID="*" ID="*" We are grateful to Tapan Mitra for pointing out errors as well as making very valuable suggestions. Thanks are due to Raouf Boucekkine and Jorge Duran for additional helpful discussions. We also thank an anonymous referee for his/her helpful comments. The second author acknowledges the financial support of the Belgian Ministry of Scientific Research (Grant ARC 99/04-235 “Growth and incentive design”) and of the Belgian Federal Goverment (Grant PAI P5/10, “Equilibrium theory and optimization for public policy and industry regulation”). Correspondence to: C. Le Van     

Voting in assemblies of shareholders and incomplete markets

Summary. An economy with two dates is considered, one state at the first date and a finite number of states at the last date. Shareholders determine production plans by voting - one share, one vote - and at -majority stable stock market equilibria, alternative production plans are supported by at most percent of the shareholders. It is shown that a -majority stable stock market equilibrium exists if where S is the number of states at the last date and J is the number of firms. Moreover, an example shows that -majority stable stock market equilibria need not exist for smaller s.Received: 23 December 2002, Revised: 14 June 2004, JEL Classification Numbers: D21, D52, D71, G39. Correspondence to: Hervé CrésThe authors are grateful to an anonymous referee for helpful comments and suggestions. Financial support from the Danish Research Councils and hospitality of HEC is gratefully acknowledged by Mich Tvede and support from Fondation HEC is gratefully acknowledged by Hervé Crés.     

食品供应链安全问题的信号博弈模型

基于食品供应链上安全信息不对称的特点以及零售企业运营状况,针对滥用食品安全标签(如无公害、绿色、有机食品标签等)的现象,以食品生产商和消费者作为博弈方,建立信号博弈模型,分析信号博弈的三种贝叶斯均衡及其条件,得出了信息不对称情况下安全食品生产商的损失函数,以及政府控制食品安全的策略。     

具缺货期不同决策支配权的两级供应链合作机制研究

从考虑市场需求固定且卖方和买方对缺货期的不同决策支配权情况,研究了两级供应链的合作机制,建立了其不完全信息的动态博弈模型,并得出其精炼贝叶斯纳什均衡,从理论上证明了卖方和买方分别占支配地位和从属地位时买方卖方应相互合作。     

农村社区公共物品的农户自愿供给——基于声誉理论的分析

农户的声誉不仅能给农户带来直接效用,它还具备信息效应与资本效应,对农户参与农村社区公共物品供给博弈的均衡路径产生重要影响。在独立博弈下,声誉的直接效用能使农户采取合作行动;在关联博弈和重复博弈中,声誉的信息及资本效应对农户的偷懒行为有很强的约束,将导致博弈进入合作均衡。因此基于声誉损益的考虑,由农户自愿供给农村社区内的公共物品会是一个有效的结果。     

Thermodynamics and process analysis for future economic scenarios

Economists are increasingly interested in forecasting future costs and benefits of policies for dealing with materials/energy fluxes, polluting emissions and environmental impacts on various scales, from sectoral to global. Computable general equilibrium (CGE) models are currently popular because they project demand and industrial structure into the future, along an equilibrium path. But they are applicable only to the extent that structural changes occur in or near equilibrium, independent of radical technological (or social) change. The alternative tool for analyzing economic implications of scenario assumptions is to use Leontief-type Input-Output (I-O) models. I-O models are unable to endogenize structural shifts (changing I-O coefficients). However, this can be a virtue when considering radical rather than incremental shifts. Postulated I-O tables can be used independently to check the internal consistency of scenarios. Or I-O models can be used to generate scenarios by linking them to econometric macro-drivers (which can, in principle, be CGE models). Explicit process analysis can be integrated, in principle, with I-O models. This hybrid scheme provides a natural means of satisfying physical constraints, especially the first and second laws of thermodynamics. This is important, to avoid constructing scenarios based on physically impossible processes. Process analysis is really the only available tool for constructing physically plausible alternative future I-O tables, and generating materials/energy and waste emissions coefficients. Explicit process analysis also helps avoid several problems characteristic of pure CGE or I-O models, viz. (1) aggregation errors (2) inability to handle arbitrary combinations of co-product and co-input relationships and (3) inability to reflect certain non-linearities such as internal feedback loops.     

Absorbing Team Games

A team is a group of people having the same motives but possibly different available actions. A team game is a game where two teams face each other. An absorbing game is a repeated game where some of the entries are absorbing, in the sense that once they are chosen the play terminates, and all future payoffs are equal to the payoff at the stage of termination. We prove that every absorbing team game has an equilibrium payoff and that there are -equilibrium profiles with cyclic structure. Journal of Economic Literature Classification Numbers: C72, C73.     

Low information nash equilibria for oligopolistic markets

This paper deals with an infinite horizon n firm oligopoly in which firms are assumed to have incomplete information about one another's actions and profit functions. An equilibrium concept is defined that is similar to the Nash non-cooperative equilibrium, but is suitable for the information assumptions of the model. The equilibrium uses a type of bounded rationality which makes firms' computations relatively easy. This is due to an implicit assumption that computation is costly and a Bayesian approach is prohibitively costly. This low information Nash equilibrium is proved to exist, and, in addition, an adaptive expectations decision process is described which, if followed by all firms, leads to the low information Nash equilibrium.     

基于公平与效率均衡的城乡和谐

已有的对城乡和谐发展问题的研究大多将注意力集中在城乡和谐发展的途径方面,却忽视了对城乡和谐衡量标准的研究.本文从公平与效率统一(均衡)的视角来解析城乡和谐的标准以及城乡和谐演进的机制,并构建了一个基于公平与效率均衡的城乡和谐发展模型.该模型揭示,城乡和谐是公平与效率均衡的函数,市场机制与政府制度的相互配合共同促进城乡和谐发展.     

总量均衡区间与宏观调控应确立的若干新原则

现代市场经济条件下,供给方调整其生产规模所需的成本可称为调节成本。由于存在调节成本,传统分析中的“总量均衡中心点”两侧便分别存在着“低位临界点”与“高位临界点”,这两点界定了一个特殊的“总量均衡区间”。“总量均衡区间”的出现对宏观调控将产生诸多重要影响,使之面临一系列新问题、新挑战。为有效应对这种新情况,在宏观调控实践中有必要相应地确立“近似均衡原则”、“适度超前原则”、“临界点原则”、“供给方原则”。