Panel‐data Estimates of the Production Function and the Revenue Function: What Difference Does It Make?*

The lack of individual firm information on output prices is a major problem in the econometrics of production. In particular, it may be expected to account for a significant share of the large discrepancies found between the cross‐sectional and time‐series estimates of capital and scale elasticities. However, taking advantage of two panel‐data samples for which we had such information, we find that estimating the revenue function (using a nominal output measure) or the production function proper (using a real output measure) makes very little difference for our results. The biases due to other sources of specification errors are probably more important.     

麝香壮骨膏中樟脑和水杨酸甲酯含量的测定

建立麝香壮骨膏中樟脑和水杨酸甲酯含量的测定方法,并测定麝香壮骨膏中两种主要有效成分的含量,以控制麝香壮骨膏生产的质量。采用GC法测定麝香壮骨膏中樟脑和水杨酸甲酯的含量;色谱条件为:毛细管柱PEG-20M,30m×0.32mm×0.25μm,柱温:165℃,进行口温度:190℃,检测器温度:200℃;N2:50Kpa,H2:50Kpa,A ir:50Kpa;进样量:1μl,毛细管柱采用分流进样方式,分流比1:10。在选定的色谱条件下,樟脑和水杨酸甲酯在0.7785-31.14μg和0.7537-15.07mg范围内与峰面积呈良好的线性关系,平均回收率分别为98.35%和102.72%,RSD分别为0.6%和1.20%;本实验为麝香壮骨膏的质量分析提供了一种准确可靠的检测方法。     

用心去做 问心无愧——高职辅导员交流的体会

高等职业教育是当前国家教育改革的一部分,作为高职院校的辅导员也就顺理成为学校管理角色中的一个焦点,高职辅导员应该做什么,怎么来做也就成为各职业院校关注和创新的关键,多沟通,多交流,多为学生着想,用心去做,这样才问心无愧,也就无怨无悔!     

R-Tresis: developing a transport model system for regional New South Wales

This paper sets out a demand modelling framework for the development of a regional transport and land use model system (R-Tresis), to be implemented for New South Wales (Australia). Traditionally, the focus of such a model system has been major metropolitan areas such as Sydney, where we have developed Tresis (Hensher, 2002). Given the growing concern about regional accessibility to many service classes, there is a need for a modelling capability that can be used to prioritize and guide policy decisions in regions that are often described as remote, rural, low density and small town. In developing a framework that is capable of integrating both demand and supply elements of transportation and land use activity, we recognized the challenges in developing primary data sources, and the high likelihood of a reliance on secondary data sources. This suggested an alternative approach to demand modelling that was not dependent on choice models; namely a suite of continuous choice models in which we capture the actual activities undertaken by each mode on both the demand and supply side at high spatial resolution.     

Inaccurate Approximation in the Modelling of Hyperinflations

In time series macroeconometric models, the first difference in the logarithm of a variable is routinely used to represent the rate of change of that variable. It is often overlooked that the assumed approximation is accurate only if the rates of change are small. Models of hyper-inflation are a case in point, since in these models, by definition, changes in price are large. In this letter, Cagan’s model is applied to Hungarian hyper-inflation data. It is then demonstrated that use of the approximation in the formation of the price inflation variable is causing an upward bias in the model’s key parameter, and therefore an exaggeration of the effect postulated by Cagan.     

矢量网络分析仪的时域功能在天线测量中的应用

介绍了利用矢量网络分析仪的时域功能测量天线系统驻波系数、增益和方向图的方法.这种方法通过确定各反射点的位置和反射大小,以及在天线增益和方向图的测量中去掉周围环境的反射影响,使测量的结果更精确.     

单位根检验的模型设定问题研究

统计量tαρ^和tτρ^会受到"噪声参数"α和δ的影响,DF在联合假设基础上给出的不变统计量仅能检验部分假设,二者的不一致可能导致通常检验程序的错误推断。依据模型设定正确和真实过程完全未知两种情况下的单位根检验,得出前者需要统计量tρ^和Φ配合使用,而后者需要遵循一定的检验程序,而DJSR程序是其中比较稳健的选择。     

通用试题库系统的设计与实现

试题库系统是教学信息化建设的重要内容,是公平、公正、合理检验学生真实水平的依据,使用试题库进行组卷有利于实现教考分离,任课教师需要按照教学大纲的要求,不断改进教学方法,切实提高教学水平.从实用的角度出发,探讨了通用试题库系统的组成方案和实现方法,在此基础上开发了通用试题库软件程序.     

监理工作中容易忽略的细节

通过对监理服务质量进行检查,指出水利工程建设监理工作中容易被忽略的一些细节问题,并提出解决这些问题的方法,对进一步提高监理服务质量具有重要意义。     

贸易开放是否改善了能源效率:基于省区间比较优势非线性的实证分析

我国作为能源消费大国和对外贸易大国,能源消费与经济增长的矛盾日益凸显,成为了我国在实现可持续发展目标的过程中的新难题。本文运用了Antweiler等提出的理论模型,使用31个省份1995-2008年的数据、采用面板固定效应进行计量回归,探讨贸易自由化与我国各省份的能源消费情况的关系。结果显示,对外贸易通过规模、技术和结构效应对能源的消费产生了程度和效果各异的影响。其中,贸易引致的结构效应则由各省的比较优势所决定并通过对外贸易影响当地的能源消费情况及变化趋势。