The Structural Relation Between Mortgage and Market Interest Rates

This paper analyzes the dynamic relationship between primary and secondary mortgage markets and the short-term and long-term market interest rates. Using a series of monthly data on fixed rate mortgage rates and GNMA rates, we explore the dependence and speed of adjustment in these primary and secondary mortgage rates to each other as well as to the long and short-term government rates. The results indicate that residential mortgage rates in general, appear to follow the long-term rate and are not very sensitive to movements in the short-term interest rate.     

基于RBF和PSO的双喉道气动矢量喷管优化设计

本文探索了一种能多变量综合优化的方法,即对喷管进行参数化设计后,用均匀试验设计(UED)将试验样本均匀散布在设计区间内,求出各性能参数后,利用径向基神经网络(RBF)对试验样本进行拟合,再用粒子群算法(PSO)对训练好的神经网络进行寻优,找出了更好的双喉道气动矢量喷管设计参数组合。数值模拟结果显示,优化后的双喉道气动矢量喷管的矢量角有了明显提高。试验表明这种优化方法具有很好的优化能力,可以用来对喷管几何外形进行参数优化。      

HOW TO MEASURE THE ECONOMIC IMPACT OF VECTOR‐BORNE DISEASES AT COUNTRY LEVEL

Vector‐borne diseases (VBDs) are widespread in less developed countries and reemerging in developed ones. Available economic studies agree that VBDs have significant effects on countries' economic outcomes, and affirm that a systematic evaluation of such effects is crucial for the efficient allocation of resources to health‐related priorities. This paper provides a comparative assessment of available methodologies for measuring the economic impact of VBDs at national level. We review both macroeconometric and micro‐based approaches, and examine advantages and disadvantages of current methods. We conclude by suggesting possible areas for future research.     

商业银行信用风险与宏观经济——基于压力测试的研究

本文采用压力测试框架,研究了宏观经济波动对商业银行信用风险的影响。文章以不良贷款率度量信用风险,以名义GDP增长率、广义货币供应量（M2）增速、居民消费价格指数（CPI）以及房地产销售价格指数作为宏观经济变量,建立了合适的宏观压力测试模型。在GDP增速放缓、CPI上升、M2增速下降的压力情景下,预测了2011年第一季度到第四季度的不良贷款率的变化路径。实证结果表明在压力情景下商业银行的不良贷款率将会显著上升。     

浅谈物理量的方向性

物理量按方向性可分为矢量和标量,本文通过实例运用平行四边形法则和正交分解法求矢量的大小和方向。进一步明确矢量方向性的物理意义。     

Do Vietnamese upland farmers benefit from high world market prices for maize?

For rural households in the north of Vietnam, maize cropping is the main source of income. In the face of the world market price increases of the recent past, we analyze the regional marketing chain of this commodity qualitatively and econometrically investigating to what extent smallholder farmers in developing countries are affected by international price movements. Vietnamese maize markets are found to be well integrated. Recent price hikes have fully transmitted along the regional supply chain so that farmers profited. Nevertheless, adverse factors such as increasing input prices have neutralized these benefits resulting in a decline in real income of smallholders.     

人民币实际汇率波动对中美贸易收支的影响——基于1990—2009年时间序列分析

基于协整理论、误差修正模型和格兰杰因果检验并根据中国和美国1990-2009年的季度数据,分析人民币实际汇率变动对中美贸易收支的影响.结果表明:影响中美贸易收支的主要因素包括美国的实际GDP、中国的实际GDP和人民币实际汇率,且三者的影响力次第减弱,中美贸易也存在明显的J曲线效应.因此,改善中美贸易失衡应扩大中国内需、调整业口结构和改革人民币汇率制度.     

Asymptotic confidence bands for the estimated autocovariance and autocorrelation functions of vector autoregressive models

This paper provides closed-form formulae for computing the asymptotic covariance matrices of the estimated autocovariance and autocorrelation functions of stable VAR models by means of the delta method. These covariance matrices can be used to construct asymptotic confidence bands for the estimated autocovariance and autocorrelation functions to assess the underlying estimation uncertainty. The usefulness of the formulae for empirical work is illustrated by an application to inflation and output gap data for the U.S. economy indicating the existence of a significant short-run Phillips-curve tradeoff.First version received: November 2002/Final version received: September 2003