Age-specific dynamic labor demand and human capital investment

To study the optimal age-specific labor demand and human capital investment at the firm level we extend the standard dynamic labor demand model by introducing ‘age’ as a second dynamic variable and distinguish between two types of workers: ‘low skilled’ and ‘high skilled’. Applying an age-structured optimal control model we derive qualitative features of the optimal age-specific hiring and training effort. For the case of a linear revenue and production function we prove that firms do not anticipate changes in adjustment costs in their optimal decisions. This result no longer holds if a nonlinear revenue or production function is considered.     

一类变质性物品的最优生产-库存策略

讨论了需求是时间的连续函数、允许缺货且缺货完全回补、变质率为常数、补货率有限的变质性物品在有限计划期内的生产-库存策略。同时证明了最优生产-库存策略的存在和唯一性,并给出了求最优策略的算法和算例。     

海洋环境管制的供需矛盾分析

本文从我国海洋环境问题的现实出发，重点分析了海洋环境管制的供求现状和矛盾，指出我国海洋环境管制的必要性和紧迫性。同时，结合我国海洋环境管制的现实，探讨了我国海洋环境管制的发展，提出我国在加强海洋环境管制的同时应拓宽思路，促进海洋环境管制的有效供给。     

The micro-foundations of intertemporal price discrimination

Summary. This paper investigates the optimality of intertemporal price discrimination for a durable-good monopoly in a model where infinitely-lived households face an intertemporal budget constraint, and consume both durable goods and non-durable goods. We prove that the optimal price of the durable good is not constant, and may decrease or increase over time. Some households may choose to purchase the durable good at a later date, and pay lower or higher prices, since the gain in discounted utility of consuming more of the non-durable good more than compensates for the loss in utility from delaying the consumption of the durable good.Received: 12 March 2004, Revised: 7 January 2005, JEL Classification Numbers: D40, D42, D91.I would like to thank C.D. Aliprantis, the Editor, and an anonymous referee for their generous advice, and constructive comments and suggestions. I have also enjoyed discussions with John Quah on the subject. Research support from the Wharton-SMU Research Centre, Singapore Management University, is gratefully acknowledged.     

构建和谐社会需要正确处理的十大关系

构建和谐社会,是一个长期的过程.在经济高速发展的轨道上,各种利益、各种关系的摩擦、碰撞是激烈的.构建和谐社会,要处理的关系非常多.其中,尤其要正确处理好十个主要方面的关系:经济增长与可持续发展的关系;人口与就业的关系;经济和教育的关系;城市和乡村的关系;高新技术产业与传统产业的关系;积累和消费的关系;内需和外需的关系;强势群体与弱势群体的关系;改革与发展的关系;中国特色与国际惯例的关系.     

Revealed preference and differentiable demand

Summary. We prove that, for finitely many demand observations, the Strong Axiom of Revealed Preference tests not only the existence of a strictly concave, strictly monotone and continuous utility generator, but also one that generates an infinitely differentiable demand function. Our results extend those of previous related results (Matzkin and Richter, 1991; Chiappori and Rochet, 1987), yielding differentiable demand functions but without requiring differentiable utility functions.Received: 1 November 2001, Revised: 5 February 2004, JEL Classification Numbers: D11, D12. Correspondence to: Kam-Chau WongThis is a much revised version of Lee and Wong (2001). We are grateful to the Referee for valuable suggestions. We also thank Professor Marcel K. Richter for his comments.     

Timing of Public Information and Cost Reduction

Received July 31, 2000; revised version received July 18, 2001     

Ecological Transfers in Non-Human Communities Parallel Economic Markets in a General Equilibrium Ecosystem Model

Synopsis: The oft-cited analogies between ecological and economic systems are exploited to develop a many-species model of population dynamics. In economies, markets are the fundamental institutions in which the interaction of demands and supplies determine the quantities and prices of goods. However, economic markets are not appropriate for ecological communities, because markets rely on voluntary exchange, whereas plants and animals engage in involuntary transfers of biomass. A properly defined counterpart to markets based on biomass transfers permits a general equilibrium model of predator/prey and competitive interactions in a many-species community. Functional response from optimal foraging and predation risk provide the demand and supply, respectively, in the biomass transfers. Energy per unit time is scarce and predators and prey make optimum choices with respect to functional response and risk avoidance based on required energy expenditures. The energy expenditures are similar to economic prices: they determine foraging strategies and are beyond the control of the predators and prey, yet they are determined by the aggregate choices of all predators and prey and by population densities. The energies acquired from foraging are used in a new way to construct difference equations that determine the population dynamics. This revised version was published online in July 2006 with corrections to the Cover Date.     

物流工程课程体系探讨

随着物流产业的快速发展，社会十分需要物流管理专业和物流工程专业本科人才。物流涉及的领域很多，有物流管理、物流系统规范、物流经济、物流信息化、物流机械、物流设施、物流自动化等。其中，物流管理专业主要偏重研究物流管理、物流系统规范、物流经济、物流信息化等领域，物流工程专业主要偏重研究物流系统规范、物流机械、物流设施、物流自动化等领域。本文根据社会需要，对物流工程人才培养的课程体系进行了探讨与研究。     

大股东资金占用与外部审计的公司治理职能

我国特殊的股权结构决定了我国上市公司的主要代理问题是大股东与中小股东之间的代理冲突。大股东往往通过各种方式如资金占用等来对上市公司进行掠夺。在西方成熟的资本市场上，审计作为一种独立的外部监督机制能够在一定程度上抑制代理冲突。那么在我国新兴的市场中，审计能否起到有效的监督作用从而抑制大股东的“利益输送行为”呢？本文从需求和供给两个方面进行了研究。实证结果发现，从需求方面来说，大股东资金占用越严重的公司越没有动机聘请高质量的审计师；从供给方面来说，审计师在出具审计报告时会考虑大股东的资金占用，大股东资金占用越严重，越有可能被出具非标准的审计意见报告。实证结果表明我国目前还不存在高质量的审计需求，但审计师能对大股乐的资金占用作出反应，从而在一定程度上抑制大股东的行为。