关键词： 计量经济学模型   参数估计   差分法   序列相关   多重共线性  

摘要： 计量经济模型能科学而准确的揭示经济现象。当然这是以模型的准确性为前提的。要保证模型的准确性 ,必须保证模型建立过程中的每一个环节的准确性。探讨了参数估计这一环节中 ,采用广义差分法估计参数时 ,容易出现的问题 ;证明了 :当模型不存在序列相关时 ,而错误的使用差分法 ,则差分模型的随机项存在序列相关 ;当模型存在序列相关时 ,而作差分变换时 ρ的取值不精确 ,则差分模型的随机项仍然存在序列相关。由此阐述了在什么情况下用差分法估计模型的参数 ,才能保证模型参数的估计量是最佳估计量 。

关键词： WATER -- Distribution   PRECIPITATION (Meteorology)   IRRIGATION  

摘要： The aim of this paper is to construct and apply a model for the allocation of water between two competing users, namely irrigation and hydropower. The model is applied in a case study of a specific water system located in North Eastern Spain. Starting with an irrigation-hydropower joint income function, we develop a constrained maximization process that takes into account the environmental, institutional and actual priority of the water rights. The resulting solution can be useful as a guide for potential bargains between users. Furthermore, we evaluate the results for different supply (precipitation) and water allotments (increase in irrigated land). The results show that there are sufficient incentives so as to reach agreements that lead to improvements in a Pareto sense without side payments.

关键词： charcoal   dynamic programming   grazing   land clearing   Senegal   vegetative biomass   woodland degradation  

摘要： A village-level dynamic, stochastic, and non-linear programming model, incorporating both economic and ecological aspects, is developed to study the complex woodland degradation processes in the sub-Saharan Africa. The emphasis is on simultaneous accounting of the effects of three major causes of woodland degradation, namely, land clearing, grazing, and extraction done for wood fuel, poles and charcoal. that has not been attempted before. The model is applied at the village level in Senegal and run for the period 1999-2020. By running different model scenarios, a number of hypotheses are tested about woodland degradation as measured through loss of vegetative biomass per unit of land. While demographic pressure was found to aggravate the woodland degradation processes, introduction of improved agricultural technology, higher cotton prices, increased rural wages, and reduced charcoal prices were found to retard the process of degradation, On the basis of the findings of this study, therefore, the role of policy makers in devising appropriate demographic and economic policies to retard the process of woodland degradation appears to be important in the sub-Saharan African nations with conditions similar to those found in Senegal. (C) 2001 Elsevier Science B.V. All rights reserved.

关键词： Economic uncertainty   Mathematical procedures   Production policy   Production costs   Arbitrage   Economic models   Production capacity   Price volatility   Valuation  

摘要： This paper develops an operational risk management model for I evaluating production efforts in manufacturing and mining industries where the resource to be exploited is nonhomogenous. Using a contingent claims methodology now commonly encountered in financial applications, we formulate a production control model in an environment characterized by market and process uncertainty, In our analysis, market risk is depicted by the output price while process uncertainty is captured by the random variability inherent in the output's yield. In this light, adjustments to the rate of production are viewed as a sequence of (nested) real options affording operating flexibility. We account for an optimal sequence of production adjustments, over a preestablished production horizon, by taking the production rate as an adapted positive real-valued process. Accordingly, techniques of stochastic control theory and contingent claims analysis (CCA) are employed to ensure value maximizing production policies are rendered in a manner consistent with an equilibrium price structure.

关键词： 电力市场需求   计量经济模型   灰色模型   组合预测   用电负荷   电力系统  

摘要： 通过对电力市场需求影响因素的分析，提出了计量经济与灰色预测的优化组合预测模型，经过论证并用实例比较得出此模型比其中任一单一模型预测误差率都小，预测结果更精确，为电力市场用电量需求提供了一个实用有效的预测方法。

关键词： 列昂捷夫(Leontief)   正矩阵A   特征值   可持续发展  

摘要： 从列昂捷夫(Leontief)正矩阵的数学性质出发,其特征值小于1的重要性,即:系统具有增值性。在特征值大于1时,尽管有时也可以使用逆矩阵法求出其静态解,从可持续发展的角度看,却并非良好解。另外,A阵变动以及非封闭A阵有其局限。

关键词： 矿床数学-经济模型   储量计算   云南   金矿床   软件包   地质统计学  

摘要： 利用地质统计学的原理和方法 ,编制出矿床数学 经济模型软件包 ,它作为一种储量计算和矿床经济评价方法。介绍了该软件包各模块的功能 ,并以元江金矿应用为例 ,展示了该软件包的功能及效果。

关键词： 电力市场改革   全电量差合竞价模式   供给   需求   电力实时交易市场   电力期货市场  

摘要： 本文首先分析了电力行业需求的基本特征 :1 .用户需求曲线是一段水平线段 ,是完全弹性的 ;2 .电网公司在用电侧的供给曲线就是用户的需求曲线 ,也是完全弹性的 ;3.每个时段 ,电网公司在发电侧的需求曲线是一条垂直的直线 ,是完全无弹性的和封顶的。然后 ,对目前电力市场竞价模式———全电量差价合约竞价模式进行了经济学分析。通过分析单个厂商的报价策略和供给曲线评价了这个模式的利弊得失。并提出 :因为电力的实时交易市场存在着一定的缺陷 ,在高负荷时市场失灵。所以要有长期合同作为实时交易的补充 ,期货市场作为现货市场的补充 ,才能完整地实现市场机制的功能。从而得出了一个基本结论———电力行业必须尽快地培育和发展期货市场。最后 ,经过理论分析和数据统计绘出了电力的总供给曲线 ,得出了总供给的基本特征 :1 .市场低负荷时的急剧下降 ;2 .市场高负荷时的陡升拐折。从而得出了电力市场的基本供求模型。

关键词： 图书馆   经济特性   图书馆经济学   文献集合   经济效益   数字图书馆   经济模型  

摘要： 近些年来,图书馆界在以各种形式宣传图书馆的社会价值.文化部把每年五月的最后一周定为全国图书馆服务宣传周以及近年来各图书馆开展的读书成果评奖和颁奖活动,其目的都是在强化社会图书馆意识,揭示图书馆所发挥的虽是潜在的、间接的然而是巨大的社会效益和经济效益。[第一段]

关键词： MACROECONOMICS   ECONOMIC forecasting   INFLATION (Finance)  

摘要： Provides insight into key aspects of the RIMINI macroeconomic model's description of the inflation mechanism and how the model is used to make economic forecasts. Overview of the RIMINI model; How the core of the inflation process is modelled in RIMINI; Transmission mechanism in RIMINI.