Sources of the great moderation: A time-series analysis of GDP subsectors

Recent work finds evidence that the volatility of the U.S. economy fell dramatically around the first quarter of 1984. We trace the timing of this so-called “Great Moderation” across many subsectors of the economy in order to better understand its root cause. We find that the interest rate sensitive sectors generally experience a much earlier volatility decline than other large sectors of the economy. The changes in Federal Reserve stabilization policies that occurred during the early 1980s support the view that an improved monetary policy played an important role in stabilizing real economic activity. We find only mild evidence that “good luck” was important and little evidence to support the claim that improved inventory management was important.     

Bias in estimating multivariate and univariate diffusions

Multivariate continuous time models are now widely used in economics and finance. Empirical applications typically rely on some process of discretization so that the system may be estimated with discrete data. This paper introduces a framework for discretizing linear multivariate continuous time systems that includes the commonly used Euler and trapezoidal approximations as special cases and leads to a general class of estimators for the mean reversion matrix. Asymptotic distributions and bias formulae are obtained for estimates of the mean reversion parameter. Explicit expressions are given for the discretization bias and its relationship to estimation bias in both multivariate and in univariate settings. In the univariate context, we compare the performance of the two approximation methods relative to exact maximum likelihood (ML) in terms of bias and variance for the Vasicek process. The bias and the variance of the Euler method are found to be smaller than the trapezoidal method, which are in turn smaller than those of exact ML. Simulations suggest that when the mean reversion is slow, the approximation methods work better than ML, the bias formulae are accurate, and for scalar models the estimates obtained from the two approximate methods have smaller bias and variance than exact ML. For the square root process, the Euler method outperforms the Nowman method in terms of both bias and variance. Simulation evidence indicates that the Euler method has smaller bias and variance than exact ML, Nowman’s method and the Milstein method.     

商业银行扁平化机构改革后金库集中管理模式探索

为适应经济金融快速发展的需要,我国商业银行在加快对组织机构改革,推进机构扁平化进程中,尤其要注重推进金库的集中化、集约化管理模式的调整.     

主成分分析法在湖南省物流规划中的应用

改革开放以来湖南省经济建设取得了长足的进步,国内生产总值屡创新高。随着农工商各行业的发展壮大,对现代物流的要求也越来越高。现代物流是一个新兴产业,继劳动力、资本之后,被广泛认可为国民经济增长的＂第三利润源泉＂。搞好省内物流管理工作,尽力减少物流成本,加强各市州之间的经济交流,对地区经济发展有重要促进作用。但是进行区域物流规划工作需要考虑的指标很多,数据量大,操作复杂。运用主成分分析方法,可将原来的许多变量简化为少数几个线性组合来解释绝大多数信息,可以达到化繁为简的目的。     

基于系统动力学的广西区域物流与经济协调发展研究

为了探讨广西区域物流与广西社会经济协调发展情况,找出制约广西物流产业的主要问题,运用系统动力学的反馈分析方法,归纳总结了研究的基本要素,建立了广西区域物流与经济协调发展的系统动力学模型,结合1990～2009年相关数据协整分析结果,应用Vensim PLE软件进行了模拟仿真,并对不同的政策进行实验,结果表明,刺激需求、合理投资以及大力培育人才等政策配合实施,能够有效地推动广西物流业和社会经济的协调发展。     

应急物流研究综述

应急物流系统的高效运作能够降低突发事件造成的危害,因而得到了理论界的广泛关注。作者围绕应急物流管理基础理论、应急物流物资筹集、应急物资调运配送、应急物资库存等几个方面的问题系统介绍了国内外有关应急物流的研究现状,并简要介绍了近一两年国内外的研究状况。     

基于6sigma的采购质量改进研究

将6sigma的管理方法引入采购质量管理中,运用6sigma定义的DMAIC五个步骤对采购过程的质量进行定义、评估、分析、改进和控制,从而达到提高采购过程质量水平的目的。     

科技企业孵化器服务标准化建设探析

文章通过对科技企业孵化器发展现状和意义的阐述,论证了科技企业孵化器开展服务标准化建设工作的必要性,并对科技企业孵化器开展服务标准化工作提出了建议。     

连续批计数抽样检验中的跳批抽样技术

文章介绍了跳批抽样的基本原理、适用范围、条件以及一般程序。文章主要对GB／T2828．3《计数抽样检验程序第3部分跳批抽样程序》技术内容进行了解读和介绍,帮助实际应用者正确运用跳批抽样程序,以达到预期目的。     

浅析新型分子筛材料的性能及检验方法—4A分子筛的标准化

4A分子筛作为一种新型材料,具有很好的吸附、分离、分散等性能,广泛应用于化工、涂料、日化、汽车及现代医学等领域。由于涉及领域较多,新修订的HG／T2524—2010《4A分子筛》标准在使用过程中可能会遇到一些问题。本文对该标准进行了解读与介绍,包括主要技术性能和检验方法,可以帮助各领域标准应用者正确运用标准,以达到预期目的。