市场化与经济增长:一个短期的因果关系检验

利用我国1999-2002年省际区域的面板数据,运用面板数据Granger因果关系检验技术,对我国市场化水平与经济增长的关联度进行了实证分析.得出市场化是经济增长的Granger原因,但是经济增长不是市场化的Granger原因的结论.     

软件限时开发方法的研究与应用

限时开发是快速应用开发的最佳实践之一。文章介绍了限时开发的基本概念和优点以及适用的项目范围,通过一个进销存软件的开发实例说明如何成功地应用限时开发方法。     

协整向量误设对相关检验的影响

常用于检验既定协整关系的统计量有tDF和tECM两种，但由于真实数据生成过程未知，估计模型中可能存在一定程度的协整向量误设，从而使统计量的分布特征受到影响。本文首先探讨tDF检验的隐含系数约束α=γ，即短期弹性等于先验长期弹性；其次分析零假设下两种统计量的分布特征，以及先验设定γ对信号噪声比q进而对tECM分布特征的影响；最后在局部备择假设下，给出两种统计量的渐近分布，并表明向量误设会降低协整检验的势，其程度与设定误差d正相关。     

中国股票市场市盈率的检验分析

市盈率高低是我国股市的关注焦点之一。本文在比较国外证券市场的市盈率之后认为我国的市盈率偏高。这种推测得到我们理论研究和模型结论的支持,我国股市市盈率由于系统风险的掩藏、股票初始发行价偏高和股市投机性等因素而呈现较高的倍数。从2004年我国股市市盈率开始下降,逐渐接近我们模型的估计值。此外,我们实证分析认为,市盈率的高低与GDP增长、股票收益波动和国有股比重等因素不存在严格的变动关系,市盈率呈现出一种随机游走的态势,市盈率不是稳定的区间值,而是一系列的动态的时间序列变量值。     

Testing for unit roots in time series models with non-stationary volatility

Many of the key macro-economic and financial variables in developed economies are characterized by permanent volatility shifts. It is known that conventional unit root tests are potentially unreliable in the presence of such behaviour, depending on a particular function (the variance profile) of the underlying volatility process. Somewhat surprisingly then, very little work has been undertaken to develop unit root tests which are robust to the presence of permanent volatility shifts. In this paper we fill this gap in the literature by proposing tests which are valid in the presence of a quite general class of permanent variance changes which includes single and multiple (abrupt and smooth-transition) volatility change processes as special cases. Our solution uses numerical methods to simulate the asymptotic null distribution of the statistics based on a consistent estimate of the variance profile which we also develop. The practitioner is not required to specify a parametric model for volatility. An empirical illustration using producer price inflation series from the Stock–Watson database is reported.     

Two-sample rank tests with truncated populations

LetX ₁,…,X _m andY ₁,…,Y _n be two independent samples from continuous distributionsF andG respectively. Using a Hoeffding (1951) type theorem, we obtain the distributions of the vector S=(S ₍₁₎,…,S _(n)), whereS _(j)=# (X _i ’s≤Y _(j)) andY _(j) is thej-th order statistic ofY sample, under three truncation models: (a)G is a left truncation ofF orG is a right truncation ofF, (b)F is a right truncation ofH andG is a left truncation ofH, whereH is some continuous distribution function, (c)G is a two tail truncation ofF. Exploiting the relation between S and the vectorR of the ranks of the order statistics of theY-sample in the pooled sample, we can obtain exact distributions of many rank tests. We use these to compare powers of the Hajek test (Hajek 1967), the Sidak Vondracek test (1957) and the Mann-Whitney-Wilcoxon test. We derive some order relations between the values of the probagility-functions under each model. Hence find that the tests based onS ₍₁₎ andS _(n) are the UMP rank tests for the alternative (a). We also find LMP rank tests under the alternatives (b) and (c).     

可转换债券市场价格与其基准股票市盈率关系初探

本文试图探讨可转换债券市场价格与其基准股票市盈率间的关系。从理论上分析,市盈率作为一个较易获得的市场指标,包含了上市公司增长机会(growth opportunity)的信息,反映了投资者对未来股价上升的预期。同时可转换债券的价格对其基准股票价格未来上升的可能性十分敏感,因此市盈率与可转换债券市场价格间应存在一定关系。但根据对上海证券交易所转债的实证分析得到:目前我国转债的市场价格与其基准股票市盈率间的关系并不显著,因而市盈率指标不能作为判断转债投资价值的有效依据。     

喷粉桩在广州地区软基处理中的应用

文章通过分析喷粉桩工作原理,总结广州地区的经验,对喷粉桩的设计提出了见解。     

宁波市上市公司盈利质量不高的原因与对策

盈利质量的不断改善和提高是企业可持续发展的根本。上市公司的主营业务利润比重与企业盈利质量存在正相关关系，即主营业务利润比重越大，上市公司的盈利质量越高，因此，提高盈利质量的关键就是要突出主业，壮大主业，不断提高主营业务利润比重，形成自己的核心盈利能力。     

Three Corrected Score Tests for Generalized Linear Models with Dispersion Covariates

We develop three corrected score tests for generalized linear models with dispersion covariates, thus generalizing the results of Cordeiro , Ferrari and Paula (1993) and Cribari-Neto and Ferrari (1995) . We present, in matrix notation, general formulae for the coefficients which define the corrected statistics. The formulae only require simple operations on matrices and can be used to obtain analytically closed-form corrections for score test statistics in a variety of special generalized linear models with dispersion covariates. They also have advantages for numerical purposes since our formulae are readily computable using a language supporting numerical linear algebra. Two examples, namely, iid sampling without covariates on the mean or dispersion parameter oand one-way classification models, are given. We also present some simulations where the three corrected tests perform better than the usual score test, the likelihood ratio test and its Bartlett corrected version. Finally, we present a numerical example for a data set discussed by Simonoff and Tsai (1994) .