Diversification, convex preferences and non-empty core in the Choquet expected utility model

Summary. We show, in the Choquet expected utility model, that preference for diversification, that is, convex preferences, is equivalent to a concave utility index and a convex capacity. We then introduce a weaker notion of diversification, namely “sure diversification.” We show that this implies that the core of the capacity is non-empty. The converse holds under concavity of the utility index, which is itself equivalent to the notion of comonotone diversification, that we introduce. In an Anscombe-Aumann setting, preference for diversification is equivalent to convexity of the capacity and preference for sure diversification is equivalent to non-empty core. In the expected utility model, all these notions of diversification are equivalent and are represented by the concavity of the utility index. Received: July 27, 1999; revised version: November 7, 2000     

健康风险冲击对农户收入的影响

本文基于中国8个省份、1354个农户、跨度15年的微观面板数据,测算了大病冲击对于农户长期收入的影响以及健康风险冲击持续的时间。我们发现:(1)大病冲击在随后的12年里对于农户人均纯收入都有显著的负面影响;(2)大病冲击对于农户的短期与中期影响使得患病户人均纯收入平均降低5%—6%;(3)健康风险冲击的长期影响可持续大约15年,并且冲击对于中低收入农户的影响更为严重。     

集团公司财务管理模式设计的探讨

本文在集团公司财务管理模式相关文献综述的基础上,提出了研究设计的框架,并据此阐述了财务管理的一般模式,分析了企业集团财务管理模式选择的影响因素,最后给出了集团公司财务管理模式的设计,以其对企业集团财务管理的实践提供指导意义。     

中国经济增长与能源消费空间面板分析

近年来面板数据广泛应用于各类统计分析,但变量的空间相关并没有引起足够的重视。本文引入空间面板回归模型研究中国各省市区经济增长和能源消费的关系。利用matlab软件及其spatial econometric模块建立和比较传统面板回归模型与空间面板回归模型,结果表明空间面板回归模型较传统面板回归模型优越,本文的研究为空间面板数据分析提供了一个应用实例。     

从国营到国有——国家股转让效果分析

本文系统地研究了从1997年到2000年在上海证券交易所和深圳证券交易所发生的国有资产局将控制权转让给国有独资企业和国有法人企业的案例数据。研究发现国家股控制权转让后公司业绩有了明显的改善,同时证券市场对国家股转让行为做出了积极的反应,产生了明显的超额收益。     

Two–step sequential sampling

Choosing the sample size in advance is a familiar problem: often, additional observations appear to be desirable. The final sample size then becomes a random variable, which has rather serious consequences.
Two such sample extension situations will be considered here. In the first situation, the observed sample variance determines whether or not to double the original sample size. In the second situation, the variances observed in two independent samples are compared; their ratio determines the number of additional observations.     

自动化立体仓库中堆垛机的设计

论述了自动化立体仓库中有轨巷道式堆垛机的结构和特点，并对有轨巷道式堆垛机的设计要点进行了分析和讨论。     

应用缓冲储备模型实证检验我国居民的储蓄行为

通过应用缓冲储备模型，实证检验我国居民的教育、医疗、住房等开支的不确定性与储蓄之间的相关性，我们发现，我国居民的预防性储蓄行为不仅显著，而且以目标储蓄率为被解释变量的模型，能够比以储蓄水平为被解释变量的模型更好地解释我国居民的“预防性储蓄”动机。建立完善的医疗保障体系、改革教育体制是降低我国巨额储蓄的必经之路。     

基于PSR模型的区域高技术产业创新要素供给评价

区域高技术产业高质量发展需要创新要素有效供给。基于PSR（压力—状态—响应)模型构建高技术产业创新要素供给评价指标体系，采用全局熵法对我国创新要素有效供给现状进行评价，并度量创新要素供给协调度，从创新要素供给综合指数和子系统协调度两个方面评价创新要素有效供给水平。在此基础上将我国区域创新要素供给分为5个梯度，并运用障碍因素诊断模型，分析影响各梯度省域高技术产业创新要素有效供给实现的主要障碍因素。研究发现，影响有效供给的主要障碍层从2009年的压力层与状态层转变为2018年的响应层与状态层，高技术产业发展水平等成为主要障碍因素。各省域应依据自身要素供给主要障碍层和障碍因子，结合自身创新要素供给所处梯度，采取针对性措施，通过强链、补链、固链相结合，实现区域高技术产业创新要素有效供给。     

Capacity constrained firms in (labor) markets with adverse selection

Summary. We discuss a competitive (labor) market where firms face capacity constraints and individuals differ according to their productivity. Firms offer two-dimensional contracts like wage and task level. Then workers choose firms and contracts. Workers might be rationed if the number of applicants exceeds the capacity of the firm. We show that under reasonable assumptions on the distribution of capacity an equilibrium in pure strategies (by the firms) exists. This result stands in contrast to the case of unlimited capacity. The utility level is uniquely determined in equilibrium. No rationing occurs in equilibrium, but it does off the equilibrium path. Received: December 29, 1999; revised version: November 30, 2000