Arrow–Debreu equilibria for rank‐dependent utilities with heterogeneous probability weighting

We study Arrow–Debreu equilibria for a one‐period‐two‐date pure exchange economy with rank‐dependent utility agents having heterogeneous probability weighting and outcome utility functions. In particular, we allow the economy to have a mix of expected utility agents and rank‐dependent utility ones, with nonconvex probability weighting functions. The standard approach for convex economy equilibria fails due to the incompatibility with second‐order stochastic dominance. The representative agent approach devised in Xia and Zhou (2016) does not work either due to the heterogeneity of the weighting functions. We overcome these difficulties by considering the comonotone allocations, on which the rank‐dependent utilities become concave. Accordingly, we introduce the notion of comonotone Pareto optima, and derive their characterizing conditions. With the aid of the auxiliary problem of price equilibria with transfers, we provide a sufficient condition in terms of the model primitives under which an Arrow–Debreu equilibrium exists, along with the explicit expression of the state‐price density in equilibrium. This new, general sufficient condition distinguishes the paper from previous related studies with homogeneous and/or convex probability weightings.     

BEHAVIORAL PORTFOLIO SELECTION: ASYMPTOTICS AND STABILITY ALONG A SEQUENCE OF MODELS

We consider a sequence of financial markets that converges weakly in a suitable sense and maximize a behavioral preference functional in each market. For expected concave utilities, it is well known that the maximal expected utilities and the corresponding final positions converge to the corresponding quantities in the limit model. We prove similar results for nonconcave utilities and distorted expectations as employed in behavioral finance, and we illustrate by a counterexample that these results require a stronger notion of convergence of the underlying models compared to the concave utility maximization. We use the results to analyze the stability of behavioral portfolio selection problems and to provide numerically tractable methods to solve such problems in complete continuous‐time models.     

The emergence of new Islamic economic and business moralities

This article aims to explore the sources of the observed transformation in the embeddedness of economic, business, and financial practices of Muslim individuals in comparison to premodern period Muslims. It argues that the predomination of instrumental reasoning in modern times, as opposed to substantive morality in everyday practice, is one of the main reasons behind the transformation of embeddedness of Muslim individuals. Instrumental reasoning, being the dominant methodology, leads to diminished submergence in social relations; that is not limited to interpersonal relationships, but further extended to the core religious acts. How such an emergent economic and business morality is reconciled with the Islamic substantive morality is examined. It is argued that “transformation of exception into norm” is the main method used to reconcile instrumental reasoning with Islamic law in fulfilling religious obligations, at least in terms of fulfilling the form and in complying with the necessities of modern life. This has led to the emergence of new economic and business moralities.     

效用理论在飞行安全风险评估中的应用

为科学划分飞行安全风险等级,将效用理论引入飞行安全风险领域,利用效用函数,建立了飞行安全风险评估模型。在分析飞行安全风险的基础上,通过定义事故或危险事件损失效应,选取合适的效用函数进行飞行安全风险的度量。模型有效区分了类似飞行事故这样高损失、低概率事件与飞行事故征候这样低损失、高概率事件风险之间的差异,克服了期望值法的局限性。最后通过实例验证了该方法的科学性和有效性。     

边际效用递减规律的再发现

本文的成果主要体现在两个方面:第一,将时间维度导入效用函数,实现了对边际效用递减规律认识的一次真正的飞跃;第二,将需求在需求要素的层次上进行分解,使边际效用递减规律有了更为准确和牢靠的基础。在这两个成果的基础上,对效用的可测量性、商品的同质性假说等问题进生了前瞻性的探讨。     

基于顾客效用的物流服务水平决策

从顾客的角度出发,以物流服务效用为基础,通过建立企业利润与物流服务水平、物流服务价格的关系模型,分析了物流服务水平与顾客效用的关系,进一步帮助物流企业确定合理的物流服务水平及其相应的价格,最终更好地满足顾客的需求和获得更大的利润。     

Accounting for optimism and pessimism in expected utility

We provide a preference foundation for decision under risk resulting in a model where probability weighting is linear as long as the corresponding probabilities are not extreme (i.e., 0 or 1). This way, most of the elegance and mathematical tractability of expected utility is maintained and also much of its normative foundation. Yet, the new model can accommodate the extreme sensitivity towards changes from 0 to almost impossible and from almost certain to 1 that has widely been documented in the experimental literature. The model can be viewed as “expected utility with the best and worst in mind” as suggested by Chateauneuf, Eichberger and Grant (Chateauneuf, Alain, Eichberger, Jürgen, Grant, Simon, 2007. Choice under uncertainty with the best and worst in mind: NEO-Additive capacities. Journal of Economic Theory 137, 538–567) or, following our preference foundation, interpreted as “expected utility with consistent optimism and pessimism”.     

Maxmin expected utility with additivity on unambiguous events

This paper provides a model of beliefs representation in which ambiguity and unambiguity are endogenously distinguished in the maxmin expected utility model of Gilboa and Schmeidler (1989). Specifically, I first extend it by getting a representation of beliefs such that the probabilistic beliefs over each ambiguous event are represented by a nondegenerate interval, while the ones over each unambiguous event are represented by a number. I then suggest a behavioral definition of ambiguity. It provides a choice theoretical foundation for the Knightian distinction between ambiguity and unambiguity.     

On the role of the utility function in the estimation of preference parameters

Modern economic theory summarizes the main characteristics of individual preferences through a definite set of parameters: risk aversion, prudence, and the elasticity of intertemporal substitution. Despite their importance, the results of the literature devoted to the parameters’ estimation are controversial. This paper highlights the neglected role that may have been played by the constraints that the quantitative definition of the parameters and the utility functions employed impose on the estimation. A number of simulation exercises are presented, which show that the same saving behaviour can be associated with quite different values of the parameters depending on the utility function adopted.     

B2C中的信誉评级模型研究

通过对信誉评级累加模型进行分析,指出了该模型具有诚信激励效用递减现象,并且分析了该现象存在的内在机理及条件;然后,提出了三种解决措施,以便减轻甚至防止诚信激励效用递减现象。通过仿真,证实了它们的有效性。