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) .     

改革以来中国农村发展地区差距分析

本文在扩展农业部门新古典经济增长模型的基础上,构建了基于农业生产率指数和农村地区劳动力就业结构的农村发展指标,以此来衡量农村发展水平及其变化状况.为了考察中国农村发展地区差距的变化趋势,我们采用面板数据单位根检验的不同方法对其收敛性进行了严格的计量检验.检验结果显示,在考虑了时间和省份特殊效应、序列相关等因素的影响后,中国各省农村发展差距以及东中西部地区农村发展的内部差距均存在条件性β收敛.     

An Empirical Investigation of the Resource-based Antecedents of Customer Value in Turbulent Environments in China

With the increasingly turbulent environment and the significant role of customers in business success, creating and delivering superior customer value by deploying unique competences of a firm has been winning more attention. However, studies of customer value seem rather divergent and fragmented, and few studies, if any, have been conducted to identify the distinctive capabilities that determine the effective and efficient creation and delivery of customer value. This paper tries to bridge such gaps and explores the fundamental antecedents of customer value in turbulent environments in perspective of a resource-based theory. Based on the structural equation models developed, we find that technological competences, integrative competence and strategic flexibility are the key resource-based antecedents of customer value while no evidence is found to support the impact of marketing competences on customer value. Furthermore, only the moderating role of marketing turbulence in the relationship between customer value and strategic flexibility is detected and supported.     

供应链协同管理模式下的信息共享机制研究

首先分析了传统供应链管理中存在的问题,通过研究供应链协同管理的内容,提出不同合作层次企业的四种协同管理模式。在此基础上,构建了供应链信息共享的组织结构,建立了信息共享的激励与约束机制。最后对信息共享机制下的供应链效益做出经济分析。     

Panel unit root tests under cross-sectional dependence

In this paper alternative approaches for testing the unit root hypothesis in panel data are considered. First, a robust version of the Dickey-Fuller t -statistic under contemporaneous correlated errors is suggested. Second, the GLS t -statistic is considered, which is based on the t -statistic of the transformed model. The asymptotic power of both tests is compared against a sequence of local alternatives. To adjust for short-run serial correlation of the errors, we propose a pre-whitening procedure that yields a test statistic with a standard normal limiting distribution as N and T tends to infinity. The test procedure is further generalized to accommodate individual specific intercepts or linear time trends. From our Monte Carlo simulations it turns out that the robust OLS t -statistic performs well with respect to size and power, whereas the GLS t -statistic may suffer from severe size distortions in small and moderate sample sizes. The tests are applied to test for a unit root in real exchange rates.     

旅游区(点)核心竞争力的实质及营建实证

旅游区(点)(以下简称旅游区)是旅游业发展的重要支撑,核心竞争力是反映一个旅游区素质和发展潜能的重要标志。文章运用竞争优势理论和核心竞争力理论并结合旅游业的自身特点,以重庆涪陵天台峡谷景区为例,探讨了旅游区核心竞争力的营造方法,并提出了以目标市场为导向,以彰显旅游资源特色、提供差异性体验为内核的旅游区核心竞争力建设思路。     

集群式供应链的竞争力及培育分析

集群式供应链是产业集群和供应链之间的藕合组织形式。本文对集群式供应链这种新型的组织形式和集群式供应链的概念进行了阐述,并对其竞争力及其培育进行分析,为集群式供应链这种新型组织方式的构建研究奠定了基础。     

基于核心技术竞争力的高新技术企业竞争优势构建

核心竞争力是企业持续竞争优势的源泉,高新技术企业的特点决定了核心技术竞争力是高新技术企业核心竞争力的关键。文章在分析高新技术企业和核心技术竞争力内涵的基础上,从如何培育核心技术竞争力和如何保持核心技术竞争力两个方面探讨了高新技术企业竞争优势的构建。     

新时代大学生就业核心竞争力培育路径研究

大学生就业问题是目前社会各界关注的热点,如何有效提升大学生就业核心竞争力显得至关重要。论文剖析大学生就业核心竞争力内涵及结构,分析大学生就业核心竞争力的主观因素、客观因素,从培养方案、职业道德、专业知识、就业指导等方面探索提升大学生就业核心竞争力的途径。     

农村人力资本投资及外溢与城乡差距实证研究

文章以人力资本溢出效应城乡两区域模型为基础,采用协整检验和误差修正模型,对中国农村人力资本投资及外溢与城乡差距的关系进行实证检验。结果表明,缩小中国城乡差距,必须加大对农村的人力资本投资。同时,要加强政府对农村的基础设施投资,为农村人力资本作用的充分发挥创造条件。