Tests based on weighted rankings in complete blocks: exact distribution and monte carlo simulation

Quade (1972, 1979) proposed a family of nonparametric tests based on weighted within-block rankings, for testing the hypothesis of no treatment effects in a complete randomized blocks layout. In this paper we give a table of the exact null distribution of these tests when the number of treatments is 3, the number of blocks is less than or equal to 14 and the block scores are linear. Moreover, a Monte Carlo study was performed to compare the powers of these tests with parametric and nonparametric competitors     

金融发展与出口贸易结构优化

在综述相关文献的基础上，利用协整检验、因果关系检验和脉冲响应函数等计量方法，根据中国1985-2006年的数据，从金融发展的规模、结构和效率三个方面对金融发展与出口贸易结构的关系进行实证分析。实证结果表明：金融发展与出口贸易结构优化之间存在着长期的协整关系，我国要促进金融体制的改革，提高金融效率，进一步促进贸易结构的优化。     

中俄相互投资的母国贸易效应比较

基于2003—2017年中俄双边投资与贸易额,借助协整检验、误差修正模型(ECM)和向量自回归模型(VAR)等方法,分析中国与俄罗斯相互投资分别对母国贸易的影响。研究结果表明:长期来看,中国对俄罗斯投资与双边贸易呈互补效应,而俄罗斯对中国投资却与双边贸易呈现替代效应;短期来看,中俄相互投资对双边贸易均不具有动态关系。中国对俄罗斯低科技含量制成品、高科技含量制成品的出口及初级制成品、资源性制成品和中等科技含量制成品的进口均与其投资之间存在着长期均衡关系;俄罗斯对中国初级制成品的出口、低科技含量制成品和中等科技含量制成品的进出口以及资源性制成品和高科技含量制成品的进口与俄罗斯在中国的投资存在着长期均衡关系。     

A gamma goodness-of-fit test based on characteristic independence of the mean and coefficient of variation

Characterization theorems in probability and statistics are widely appreciated for their role in clarifying the structure of the families of probability distributions. Less well known is the role characterization theorems have as a natural, logical and effective starting point for constructing goodness-of-fit tests. The characteristic independence of the mean and variance and of the mean and the third central moment of a normal sample were used, respectively, by Lin and Mudholkar [1980. A simple test for normality against asymmetric alternatives. Biometrika 67, 455–461] and by Mudholkar et al. [2002a. Independence characterizations and testing normality against skewness-kurtosis alternatives. J. Statist. Plann. Inference 104, 485–501] for developing tests of normality. The characteristic independence of the maximum likelihood estimates of the population parameters was similarly used by Mudholkar et al. [2002b. Independence characterization and inverse Gaussian goodness-of-fit. Sankhya A 63, 362–374] to develop a test of the composite inverse Gaussian hypothesis. The gamma models are extensively used for applied research in the areas of econometrics, engineering and biomedical sciences; but there are few goodness-of-fit tests available to test if the data indeed come from a gamma population. In this paper we employ Hwang and Hu's [1999. On a characterization of the gamma distribution: the independence of the sample mean and the sample coefficient of variation. Ann. Inst. Statist. Math. 51, 749–753] characterization of the gamma population in terms of the independence of sample mean and coefficient of variation for developing such a test. The asymptotic null distribution of the proposed test statistic is obtained and empirically refined for use with samples of moderate size.     

论重复训练与学生计算技能的相关性

本文用教育测量学的方法 ,以数理统计为工具论证了重复训练与学生计算技能之间的相关关系 ,是对教学理论的一种探索。     

Inference for functions of parameters in discrete distributions based on fiducial approach: Binomial and Poisson cases

In this article, we propose a simple method of constructing confidence intervals for a function of binomial success probabilities and for a function of Poisson means. The method involves finding an approximate fiducial quantity (FQ) for the parameters of interest. A FQ for a function of several parameters can be obtained by substitution. For the binomial case, the fiducial approach is illustrated for constructing confidence intervals for the relative risk and the ratio of odds. Fiducial inferential procedures are also provided for estimating functions of several Poisson parameters. In particular, fiducial inferential approach is illustrated for interval estimating the ratio of two Poisson means and for a weighted sum of several Poisson means. Simple approximations to the distributions of the FQs are also given for some problems. The merits of the procedures are evaluated by comparing them with those of existing asymptotic methods with respect to coverage probabilities, and in some cases, expected widths. Comparison studies indicate that the fiducial confidence intervals are very satisfactory, and they are comparable or better than some available asymptotic methods. The fiducial method is easy to use and is applicable to find confidence intervals for many commonly used summary indices. Some examples are used to illustrate and compare the results of fiducial approach with those of other available asymptotic methods.     

Intermediate efficiency by shifting alternatives and evaluation of power

We study a modification of the notion of asymptotic intermediate efficiency of statistical tests by defining it in terms of shifting alternatives. We prove a theorem providing conditions for its existence and show that this modification is closely related to the original Kallenberg's asymptotic intermediate efficiency in a quite general setting. Next, we find estimates for differences between powers of the Neyman–Pearson test under original alternatives and that of a given test under shifted alternatives. We also present some simulation results. They attest to consistency of theoretical results with observed empirical powers for quite small sample sizes.     

Goodness-of-fit tests for general linear models with covariates missed at random

In this paper, we consider a model checking problem for general linear models with randomly missing covariates. Two types of score type tests with inverse probability weight, which is estimated by parameter and nonparameter methods respectively, are proposed to this goodness of fit problem. The asymptotic properties of the test statistics are developed under the null and local alternative hypothesis. Simulation study is carried out to present the performance of the sizes and powers of the tests. We illustrate the proposed method with a data set on monozygotic twins.     

Small-sample likelihood inference in extreme-value regression models

We deal with a general class of extreme-value regression models introduced by Barreto-Souza and Vasconcellos [Bias and skewness in a general extreme-value regression model, Comput. Statist. Data Anal. 55 (2011), pp. 1379–1393]. Our goal is to derive an adjusted likelihood ratio statistic that is approximately distributed as χ² with a high degree of accuracy. Although the adjusted statistic requires more computational effort than its unadjusted counterpart, it is shown that the adjustment term has a simple compact form that can be easily implemented in standard statistical software. Further, we compare the finite-sample performance of the three classical tests (likelihood ratio, Wald, and score), the gradient test that has been recently proposed by Terrell [The gradient statistic, Comput. Sci. Stat. 34 (2002), pp. 206–215], and the adjusted likelihood ratio test obtained in this article. Our simulations favour the latter. Applications of our results are presented.     

中国石油消费与经济发展之间经济计量分析——基于产业层面的研究

本文分析了中国经济发展过程中石油消费总量的变化趋势,并对1985~2006年不同产业的石油消费和产业增加值等基本状况进行了深入研究。在此基础上,运用协整理论和Granger因果关系检验理论,按照不同的产业对中国石油消费和产业增加值之间的关系进行了实证分析。结果表明,中国第一、三产业石油消费量与产业增加值之间不存在相关关系,中国第二产业的石油消费量与产业增加值之间存在正相关关系,但无因果关系。