Quality Competition and Social Welfare in Markets with Partial Coverage: New Results*

We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant.     

整合产品服务系统——实现循环经济的新途径

整合产品服务系统(IPSS)是一种社会组织创新战略,通过将目前仅生产和销售有形产品的相互分离的工业生产与服务体系有机地整合,以比传统生产和消费模式更低的环境代价,有效满足顾客需求。作为对传统商业模式的革命性变革,整合产品服务系统是促进可持续发展和循环经济的有效手段和必由之路。本文讨论其产生的背景,给出其定义和理论框架,介绍其发展历程,以便为我国发展循环经济提供借鉴。     

物流按地域属性分类的理论探索

从物流按地域属性分类切入，首先介绍了物流的地域属性，然后列出目前物流按地域属性分类的常见分法并对它们的不足之处详细分析，在此基础上，最后提出其科学的分类方法并对其中的概念进行一一解释。     

The graph of Lindahl correspondence as the unique von Neumann-Morgenstern abstract stable set

In this paper, we consider a continuum economy with a finite number of types of agent, and several private and public goods. The main result of the paper is that the graph of the equal-treatment Lindahl equilibria mapping is the unique abstract stable set with respect to the dominance relation in economies with crowding effects introduced by Vasil'ev et al. in 1995. The external stability of this mapping implies that, for any equal-treatment allocation x in , that is not a Lindahl equilibrium, there exists a subeconomy of such that one of its equal-treatment Lindahl allocations blocks x. This result is a counterpart of the theorem of Mas-Colell for Aumann's atomless market with private goods.     

Job satisfaction and gender: Why are women so happy at work?

By most objective standards, women's jobs are worse than men's, yet women report higher levels of job satisfaction than do men. This paper uses a recent large-scale British survey to document the extent of this gender differential for eight measures of job satisfaction and to evaluate the proposition that identical men and women in identical jobs should be equally satisfied. Neither the different jobs that men and women do, their different work values, nor sample selection account for the gender satisfaction differential. The paper's proposed explanation appeals to the notion of relative well-being, especially relative to workers' expectations. An identical man and woman with the same jobs and expectations would indeed report identical job satisfaction, but women's expectations are argued to be lower than men's. This hypothesis is supported by the finding that the gender satisfaction differential disappears for the young, the higher-educated, professionals and those in male-dominated workplaces, for all of whom there is less likely to be a gender difference in job expectations.     

Proportionally adjusted marginal pricing method to share joint costs

We consider the cost sharing problem with divisible demands of heterogeneous goods. We propose a cost sharing method called Proportionally Adjusted Marginal Pricing (PAMP) method. PAMP is a nonadditive (in the cost function) extension of average cost pricing. We introduce an axiom called Local Independence (LI) and use LI together with Continuity, Proportionality, and Scale Invariance to characterize PAMP. Received: 23 March 2001 / Accepted: 16 November 2001 I thank Yves Sprumont, Hervé Moulin, and Ahmet Alkan for discussions, comments and suggestions. Thanks also go to the associate editor and the referees, whose comments and suggestions greatly improve the paper.     

智能车辆流量检测器的设计与实现

本文介绍了利用单片机如何实现智能环形线圈车辆检测器，讨论了此类检测器的软硬件设计要点。给出了相应的接口电路。     

农产品物流不畅的原因分析及改善

农产品物流不畅影响农民的增收,而农产品物流不畅的根源在于我国农业传统的生产方式、经营方式和技术.改善和发展农产品物流需要政府和企业共同努力.     

Distribution-free tests for comparing several treatments with a control

Abstract  In this paper we propose distribution-free treatments versus control tests for the one- and two-way classifications. The null distribution properties are shown to be equivalent to those of well-known statistics for which critical values have been extensively tabled. Asymptotic relative efficiencies with respect to corresponding normal theory competitors are derived and optimal designs for the allocation of experimental units to the treatments and control are obtained.     

废旧电子产品回收网络研究

废旧电子产品的污染问题已经越来越被重视，孕育在废旧电子产品的价值也已经被企业逐渐认识．而现行的回收网络过于简单，不利于产品的回收处理和价值恢复。本文从讨论废旧电子产品的污染和回收价值谈起．就电子产品回收的璁状提出了一个以制造企业为中心、全社会广泛参与的回收网络模型。