中国区域经济发展差异收敛的非线性分形分析

中国区域经济发展差异收敛分析可利用非线性分形理论及其主要方法R S法的原理及模型 ,对中国 1 978～ 1 998年衡量区域经济发展差异收敛的时间序列变量指标进行了多维R S实证分析 ,得到了区域经济发展差异演变的赫斯特指数H值和分维D值。分析结果显示 ,我国区域经济发展差异的演化满足赫斯特 (Hurst)律 ,具有明显的分形特征 ,区域经济发展差异在其演变过程中具有明显的持续性规律 ,即区域经济发展差异没有呈现出收敛 (趋同 )而呈现发散 (趋异 )态势 ,该结论与我国区域经济发展实际态势基本一致     

Testing for panel cointegration in an error-correction framework with an application to the Fisher hypothesis

In this article, three innovative panel error-correction model (PECM) tests are proposed. These tests are based on the multivariate versions of the Wald (W), likelihood ratio (LR), and Lagrange multiplier (LM) tests. Using Monte Carlo simulations, the size and power of the tests are investigated when the error terms exhibit both cross-sectional dependence and independence. We find that the LM test is the best option when the error terms follow independent white-noise processes. However, in the more empirically relevant case of cross-sectional dependence, we conclude that the W test is the optimal choice. In contrast to previous studies, our method is general and does not rely on the strict assumption that a common factor causes the cross-sectional dependency. In an empirical application, our method is also demonstrated in terms of the Fisher effect—a hypothesis about the existence of which there is still no clear consensus. Based on our sample of the five Nordic countries we utilize our powerful test and discover evidence which, in contrast to most previous research, confirms the Fisher effect.     

人民币汇率、升值预期与外汇储备相关性研究

在理论分析的基础上,采用结构变化单位根(ZA)检验对数据进行处理,运用结构变化协整(GH)检验实证研究人民币汇率、人民币升值预期与外汇储备之间的相关性.实证结果表明:人民币汇率(名义有效汇率及实际有效汇率)与外汇储备之间不存在普通意义上的协整关系;而人民币升值预期与外汇储备之间存在发生结构变化的长期协整关系,人民币升值...     

SUBSAMPLING THE JOHANSEN TEST WITH STABLE INNOVATIONS

By taking into account the thick-tail property of the errors, cointegration analysis in vector error-correction models with infinite-variance stable errors is a natural generalization of cointegration analysis in error-correction models with normally distributed errors. We study the Johansen test for cointegrated systems under symmetric stable innovations with discrete spectral measures. The results show that the distributions of the Johansen test statistics under these innovations involve nuisance parameters. To overcome the problem of nuisance parameters, we implement a nonparametric subsampling procedure. We document some subsampling simulation results and demonstrate in an empirical example how the test can be used in practice.     

动态广义最小二乘法在面板协整中的应用研究

在进行非平稳面板数据的协整分析时,使用动态最小二乘法（DOLS）可以有效消除内生性问题,从而得到具有渐进正态分布的统计量。但在小样本条件下,由于可使用解释变量差分项的阶数有限,导致模型中均衡误差项的序列相关,使得DOLS统计量出现严重的检验水平畸变。为此,本文将单一时间序列的动态广义最小二乘法（DGLS）应用于非平稳的同质面板数据模型。在序贯极限分布的条件下,DGLS统计量仍具有正态的条件极限分布。而仿真实验表明,对于非平稳的同质面板数据模型,即使在均衡误差项存在高序列相关的条件下,DGLS统计量仍具有较好的小样本性质。     

SHIBOR市场利率期限结构实证研究

基于2006年10月8日～2008年10月9日间上海银行间同业拆放利率市场的日数据,利用单位根和协整检验对预期理论对于利率期限结构不同部分的适用性差异进行了研究,发现上海银行间同业拆放利率系统存在两个随机趋势,即短端利率的波动趋势和长端利率的线性漂移趋势,因此预期理论对于上海银行间同业拆放利率市场的利率期限结构整体上是不适用的,但是对于期限结构的短端和长端则分别适用。在此基础上,分别对短端利率和长端利率两个子系统建立了误差修正模型以刻画其动态特性,发现货币政策的效应沿上海银行间同业拆放利率期限结构衰减,从而会造成收益率曲线产生非平行变动,甚至扭曲。此外,还发现隔夜拆借利率的动态特性表现出背离长期均衡关系的趋势。     

BAYESIAN ANALYSIS OF A FRACTIONAL COINTEGRATION MODEL

The concept of fractional cointegration, whereby deviations from an equilibrium relationship follow a fractionally integrated process, has attracted some attention of late. The extended concept allows cointegration to be associated with mean reversion in the error, rather than requiring the more stringent condition of stationarity. This paper presents a Bayesian method for conducting inference about fractional cointegration. The method is based on an approximation of the exact likelihood, with a Jeffreys prior being used to offset identification problems. Numerical results are produced via a combination of Markov chain Monte Carlo algorithms. The procedure is applied to several purchasing power parity relations, with substantial evidence found in favor of parity reversion.     

Revealing age-specific past and future unrelated costs of pneumococcal infections by flexible generalized estimating equations

We aimed to study the excess health-care expenditures for persons with a known positive isolate of Streptococcus pneumoniae. The data set was compiled by linking the database of the largest Belgian Sickness Fund with data obtained from laboratories reporting pneumococcal isolates. We analyzed the age-specific per-patient cumulative costs over time, using generalized estimating equations (GEEs). The mean structure was described by fractional polynomials. The quasi-likelihood under the independence model criterion was used to compare different correlation structures. We show for all age groups that the health-care costs incurred by diagnosed pneumococcal patients are significantly larger than those incurred by undiagnosed matched persons. This is not only the case at the time of diagnosis but also long before and after the time of diagnosis. These findings can be informative for the current debate on unrelated costs in health economic evaluation, and GEEs could be used to estimate these costs for other diseases. Finally, these results can be used to inform policy on the expected budget impact of preventing pneumococcal infections.     

寿险、非寿险发展与经济增长——基于国际视角的实证分析

以1986—2007年48个国家的面板数据为样本,通过模型选择的检验,采用固定效应模型和误差修正模型,以人均寿险保费、人均非寿险保费为代表变量对经济发展的影响及两者之间的互动发展情况进行实证分析。结果表明：这三者之间具有明显的协整关系,经济越发达的国家或地区,保险市场的发展对经济增长的促进作用越大;寿险业与非寿险业对经济的影响存在区别,非寿险业对经济的促进作用在短期内更加明显,而寿险业对经济的促进作用则体现为长期影响。     

Accelerated Estimation of Switching Algorithms: The Cointegrated VAR Model and Other Applications

Restricted versions of the cointegrated vector autoregression are usually estimated using switching algorithms. These algorithms alternate between two sets of variables but can be slow to converge. Acceleration methods are proposed that combine simplicity and effectiveness. These methods also outperform existing proposals in some applications of the expectation–maximization method and parallel factor analysis.