The long-run Phillips curve and non-stationary inflation

Modern theories of inflation incorporate a vertical long-run Phillips curve and are usually estimated using techniques that ignore the non-stationary behaviour of inflation. Consequently, the estimates obtained are imprecise and unable to test the veracity of a vertical long-run Phillips curve. We estimate a Phillips curve model taking into account the non-stationary properties in inflation and identify a small but significant positive relationship between inflation and unemployment. The results also provide some evidence that the trade-off between inflation and the rate of unemployment in the short-run worsens as the mean rate of inflation increases.     

Forecasting inflation with an uncertain output gap

The output gap is a crucial concept in the monetary policy framework, indicating demand pressure that generates inflation. However, its definition and estimation raise a number of theoretical and empirical questions. This paper evaluates a series of univariate and multivariate methods for extracting the output gap in Norway, and compares their value added in predicting inflation. We find that models including the output gap have better predictive power than models based on alternative indicators, and they forecast significantly better than simple benchmark models. Furthermore multivariate measures of the output gap perform better than the univariate gaps. Comments from two anonymous referees, Q. Farooq Akram, Tommy Sveen, Ken West, Fredrik Wulfsberg and seminar participants in Norges Bank are gratefully acknowledged. All mistakes remain our own. The views expressed are those of the authors and do not necessarily represent those of Norges Bank.     

基于LABVIEW的水泵测试系统的建立

通过Labview开发水泵测试系统平台,使水泵的流量、扬程等水利性能参数及配套电机的电量性能参数采集实现图形化,并通过曲线拟合方式绘制出曲线,依据标准计算判定水泵的性能指标。     

五次函数及其性质的研究

本文通过对三次函数和四次函数及其曲线性质的研究,利用各次幂的系数来确定五次函数的极值点以及拐点的存的条件,并给出了求拐点和极值的计算公式。     

大掺量磨细粉煤灰混凝土单轴受压应力应变全曲线的试验研究

普通混凝土和高强混凝土的应力应变曲线,国内外已开展了大量的研究。但有关掺磨细粉煤灰混凝土应力应变全曲线资料却不多见,本文配合粉煤灰混凝土的推广应用,对其单轴受压性能及应力应变关系进行试验研究,同时给出了适用于不同强度等级掺磨细粉煤灰混凝土受压应力应变全曲线的统一数学表达式,与试验曲线吻合较好,可供进一步研究参考。     

基于非线性主成分分析的信用评估模型研究

传统的主成分分析（PCA）本质上是一种线性映射算法,无法有效处理非线性关系的数据。本文在分析自联想神经网络（AANN）的基础上,借鉴传统PCA方法中的序数主成分概念,提出了基于顺序自联想神经网络（SAANN）的非线性主成分分析法（NLPCA）。进一步,结合神经网络（NN）和Logisitic模型,以我国上市公司为研究对象,分别构建了基于NLPCA-NN和NLPCA-Logisitic的信用评估模型。实证结果及ROC曲线分析表明,本文构建的NLPCA相比传统的线性PCA方法能有效地实现数据的非线性特征提取与降维,提高模型预测性能。此外,实证结果还表明,在相同PCA方法处理数据的条件下,神经网络模型的信用评估效果要好于Logisitic模型。     

如何认识宏观经济与就业的关系

中国的就业体制改革和劳动力市场发育。是整体经济改革的重要方面。在这个改革过程中,形成了符合市场经济原则的政府积极就业政策体系,市场在配置劳动力资源中发挥了基础的作用。但这个改革任务还没有完成。如果宏观经济政策仅仅关注经济增长．没有真正把就业作为政策制定的出发点。不仅不能取得良好的就业扩大效果,也不能实现经济增长的初衷。在宏观经济政策选择中理解就业与经济增长和经济周期的关系,完善市场经济条件下的就业体制,实现就业与通货膨胀之间的平衡,具有十分重要的意义和紧迫性。     

我国有利于穷人的经济增长问题研究

本文以“贫困增长曲线”为理论基础,实证分析了1978-2006年来我国的经济增长是否是有利于穷人的经济增长。研充结果表明：1978-2006年间,无论对于城镇地区还是农村地区,经济增长都不是有利于穷人的经济增长;只有1978-1985年间对于城镇地区而言,经济增长才是有利于穷人的。之所以会出现这样的结果,主要原因是在经济增长的同时,我国收入分配不平等的程度不断加深,从而部分抵消了经济增长的减贫效果,使得穷人从经济增长中的获益少于非穷人。     

An alternative functional form for estimating the Lorenz curve

We propose a simple single parameter functional form for the Lorenz curve. The new specification is fitted to existing data sets and is shown to provide a better fit than existing single parameter Lorenz curves for the given data.     

Using inverted Engel curves to estimate material standards of living in a household

This article demonstrates how to estimate latent total consumption expenditure or material standard of living in households by inverting estimated Engel curves. While the conventional estimator, total purchase expenditure, is unbiased for latent total household consumption expenditure, it is not variance minimizing since it is an un-weighted sum. In two stages, this article derives a variance-minimizing, unbiased estimator by first estimating and inverting Engel curves; then combining the estimators from the inverted Engel curves. The employed latent variable method allows for utilization of non-expenditure relations. The suggested method may help improve the accuracy in studies of consumption inequality and tax evasion.