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.     

基于复杂供应链库存管理策略的系统动力学研究

在分析了具有不同提前期和加工时间的复杂供应链特点基础上，研究了混合CONWIP／Kanban库存管理思想与同步CONWIP库存管理思想在复杂供应链上的应用。同时借助Vensim建模平台。针对这两种管理思想建立了基于复杂供应链系统的动态仿真模型，并对模拟结果进行了分析。     

VMI在虚拟企业供应链管理中的应用

VMI作为一种新的供应链管理方法，在优化供应链效果方面是十分显著的。通过分析虚拟企业供应链管理的特点，建立了虚拟企业应用VMI管理的模型。而且，分析了VMI系统的核心运作模式，提出了虚拟企业中如何对VMI系统进行管理。     

基于模糊层次分析的供应链绩效评价

供应链管理的绩效评价,对于供应链运作和管理是至关重要的.本文在对供应链上单个企业的绩效评价指标的局限性的分析基础上,阐述了供应链指标体系作用及设计原则,并构建了供应链绩效评价指标体系,同时利用层次分析法确定各指标的权重,最后运用模糊综合评价方法从定量的角度对企业绩效评价方法进行研究,并给出评价过程.     

Theory and practice of monetary policy

Summary. We consider an optimally managed renewable resource with stochastic non-concave growth function. We characterize the conditions under which the optimal policy leads to global extinction, global conservation and the existence of a safe standard of conservation. Our conditions are specified in terms of the economic and ecological primitives of the model: the biological growth function, the welfare function, the distribution of shocks and the discount rate. Our results indicate that, unlike deterministic models, extinction and conservation in stochastic models are not determined by a simple comparison of the growth rate and the discount rate; the welfare function plays an important role.Received: 20 October 2004, Revised: 28 February 2005, JEL Classification Numbers: D90, O11, O41, Q32.Santanu Roy: Correspondence toResearch on this paper was completed when the second author visited Cornell University in July, 2003. We thank the Center for Analytic Economics and the Department of Economics at Cornell University for making this research visit possible. The current version has gained considerably from the comments made by an anonymous referee.     

Policy Discrimination with and without Interpersonal Comparisons of Utility

Can the Pareto criterion guide policymakers who do not know the true model of the economy? If policymakers specify ex ante preferences for agents, then Pareto improvements from a distorted status quo are usually possible, and with more commodities than states, one can implement almost every Pareto optimum. Unlike the standard second welfare theorem, planners cannot dictate allocations: agents must trade. Unfortunately ex ante preferences impose interpersonal comparisons. If policymakers merely aim to maximize some social welfare function then optimal policies form an open set; hence small changes in the environment do not necessitate any policy response. Planners with symmetric information about agents can sometimes intervene without making interpersonal comparisons.     

水运交通节能效益评估

本文核算了1985～2000年我国内河水路货运交通的节能量,以及由此减排的主要大气污染物量。并通过合适的环境经济方法将节能物理量转化为货币量。结果表明:(1)相对于1980年我国水运能耗水平,1985～2000年我国水路货运业每年直接节约油品6200～9200吨,折合货币量1900万～2800万元;(2)若相对于汽车运输,我国水运每年直接节约油品9万～12万吨,折合2.5亿～3.2亿元。若从开源系统考虑,万元节约油品、减排污染物以及由此获得的经济收益量是其直接值的1.17～1.09倍。     

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.     

政府国库资金、货币供给与货币政策有效性

政府财政行为对货币政策效应的影响是宏观经济学的一个热点问题,文章从政府资产角度出发,运用1994～2005年中国国库资金季度数据,采用协整分析方法对政府国库资金、货币供给和货币政策有效性问题,作实证检验。研究表明:(1)国库资金增减导致基础货币收缩和扩张,短期内国库资金变动会使货币供应量发生显著的反向波动,国库资金是货币供应量的Granger因,国库资金对货币供应量波动有较高的解释力,央行的货币供给由于国库资金而产生被动性。(2)国库资金与货币政策有效性之间存在密切关系,货币当局将国库资金变量纳入货币政策中介目标监控体系,有助于提高货币政策的有效性,国库资金成为财政政策与货币政策新的结合点。