中国宏观经济和金融总量结构变化及因果关系研究

宏观经济和金融总量是否平稳是研究总量动态特征以及总量之间关系的前提。本文在考虑经济中结构变化的基础上对中国宏观经济和金融总量的时序列是具有单位根的非平稳还是分段趋势平稳进行了研究,结果发现在检验的10个总量中,有6个,即实际GDP、人均实际GDP、就业、实际银行信贷、实际储蓄负债和实际固定投资等总量的时序列是围绕着1个或2个结构断点的分段趋势平稳。分段趋势平稳的结论对于政策主导下的长期经济发展战略和短期经济稳定措施是否有效,以及总量之间关系的研究具有重要的启示。在单位根检验结果的基础上,本文还对消除趋势后的分段趋势平稳总量之间的因果关系进行了分析。     

MCS—51单片机间的远程数据通信

本文介绍了利用MCS—51单片机现有软件和硬件资源实现远程数据通信的一种简单实用的方法。由这一方法构成的系统具有较低的成本和较高的可靠性。文中最后给出了接收和发送实验程序清单。     

On Modelling the Persistence of Profits in the Long Run: A Test of the Standard Model for 156 US Companies, 1950–99

‘Persistence of profits’ studies of competitiveness across samples of firms, and for individual firms, have almost always employed a simple first order autoregression model. Reservations over the use and interpretation of the AR1 in this context raise questions both over the reliability of previous results, and for future research strategy. We test the standard model on a common sample of 156 US companies over a 50 year period against a recently proposed, alternative model that adopts structural time series methods. A statistically significant degree of consistency is found between the two approaches in identifying firms persistently above or below the competitive norm in the long run. However, the structural time series method detects a much higher overall incidence of persistence, and appears to offer advantages in cases where the profit dynamics are more complex.     

Model selection in univariate time series forecasting using discriminant analysis

When a large number of time series are to be forecast on a regular basis, as in large scale inventory management or production control, the appropriate choice of a forecast model is important as it has the potential for large cost savings through improved accuracy. A possible solution to this problem is to select one best forecast model for all the series in the dataset. Alternatively one may develop a rule that will select the best model for each series. Fildes (1989) calls the former an aggregate selection rule and the latter an individual selection rule. In this paper we develop an individual selection rule using discriminant analysis and compare its performance to aggregate selection for the quarterly series of the M-Competition data. A number of forecast accuracy measures are used for the evaluation and confidence intervals for them are constructed using bootstrapping. The results indicate that the individual selection rule based on discriminant scores is more accurate, and sometimes significantly so, than any aggregate selection method.     

Time Series Modelling of Daily Tax Revenues

We provide a detailed discussion of time series modelling of daily data in general and daily tax revenues in particular. The main feature of the daily tax revenue series is the pattern within calendar months. Standard time series methods for seasonal adjustment and forecasting cannot be used since the number of banking days per calendar month varies and because there are two levels of seasonality: between months and within months. We propose a daily time series model based on unobserved components that allows for the classic decomposition into trend, seasonal plus irregular, but it also includes components for intra-monthly, trading-day and length-of-month effects. Such components typically rely on stochastic cubic spline, polynomial and dummy variable functions. State space techniques are used for the recursive computation of the likelihood and forecasts functions with special allowance for irregular spacing. The model is operational for daily forecasting at the Dutch Ministry of Finance. We present the model specification and discuss estimation and forecasting results up to December 1999. A comparative forecast evaluation is also presented.     

Investigation on Dumpling Issue——Remarks from China's State Council Information Office

From the very beginning of the dumpling incident,China has pav great concernontheoroblem and moved rapidly to find the reason and take further actions.Series of investigations carried in both countries by co-organized experts'team received a primary fruit as the true picture of the incident.Each time,China IS sparing no effort responsibly to solve the products quality dilemma,which other countries face in the same.     

高职财务会计教学中的串联和延伸

会计改革不断推进，如何培养学生的学习能力和创新意识，以适应会计方法、内容、体系等的不断更新？这就需要我们不断探索新的教学方式，将一节课的核心内容和重要知识点，进行有机的结合连接，并向外扩展辐射，形成一个个“知识点群”。引导学生掌握系统知识，提高学习与实践能力，是高职财务会计教学中的一项重要内容。     

Estimation of the effective bid-ask spread on high frequency Danish bond data

In this paper the effective bid-ask spread is estimated using 12 high frequency Danish bond samples. A clear-cut MA(1)-model for the mean of the return series, and a GARCH(1,1)-model for the variance, are found. Basically, Roll's model is used, but three different methods of calculating the first-order autocovariance are suggested. Each of these in turn produces three possible ways of estimating the effective bid-ask spread. First, Roll's original autocovariance estimate is used. Second, the autocovariance is calculating using the parameters of an estimated MA(1) model. Third, the autocovariance is obtained from the parameters of a joint MA(1)-GARCH(1,1) model. By means of bootstrapping the standard error of the bid-ask spread estimates are found. It is shown that the gain in efficiency, measured by the relative difference in the standard error of the estimates, is 29% when going from method one to method two, but only 1% when going from method two to method three. These results indicate that the extra gain in efficiency obtained by taking account of the MA(1) structure of the data is noteworthy, but the gain when incorporating the GARCH-effects is negligible.     

Export-led growth: a survey of the empirical literature and some non-causality results. Part 1

The economic development and growth literature contains extensive discussions on relationships between exports and economic growth. One debate centres on whether countries should promote the export sector to obtain economic growth. An abundant empirical literature on this export-led growth (ELG) hypothesis has followed. We aim to contribute to this literature in two ways. In this paper, part 1, we provide a comprehensive survey of more than 150 export-growth applied papers. We describe the changes that have occurred, over the last two decades, in the methodologies used empirically to examine for relationships between exports and economic growth, and we provide information on the current findings.The last decade has seen an abundance of time series studies that focus on examining for causality via exclusions restrictions tests, impulse response function analysis and forecast error variance decompositions. Our second contribution is to examine some of these time series methods. We show, in part 2, that ELG results based on standard causality techniques are not typically robust to specification or method. We do this by reconsidering two export-led growth applications – Oxley’s (1993) study for Portugal, and Henriques and Sadorsky’s (1996) analysis for Canada. Our results suggest that extreme care should be exercised when interpreting much of the applied research on the ELG hypothesis.     

Time Series Analysis of Strategic Pricing Behavior in the US Airline Industry

A positive relationship betweencompetitive pressure and technical efficiency has been demonstratedby several studies; other studies hold forth that airline marketsbehave strategically. We bring these two literatures togetherby presenting a time series methodology to examine strategicpricing behavior and discussing the implications for airlineefficiency. We find evidence of dynamic, route-level, parallel( i.e. strategic) pricing despite highly variable price structures.A stable price relationship is consistent with successful coordinationof dynamic oligopolists and may highlight those routes wheresignificant market power exists. In light of previous research,this indicates that the airlines on these routes may not be attainingmaximum technical efficiency. For policy makers, this methodologyis useful for analyzing other markets which behave strategically.