双向FDI与经济增长的实证研究

从双向FDI的角度分析OFDI和IFDI与经济增长的关系。选取双向FDI对经济增长的3个主要影响因素,分别对双向FDI与GDP、投资、净出口和产业结构的关系进行实证分析。研究发现:双向FDI对于GDP和投资都具有拉动作用;IFDI对投资的影响滞后4期才能产生,对净出口的增长起到正向促进作用;OFDI的扩大不利于净出口的增长;双向FDI与三次产业都存在较强的灰色关联度。据此,提出改善对内对外投资环境、发挥双向FDI对固定资产投资和净出口的促进作用、强化双向FDI对产业结构的调整作用等建议。     

Testing the Equality of Two Exponential Distributions

This paper proposes an overlapping-based test statistic for testing the equality of two exponential distributions with different scale and location parameters. The test statistic is defined as the maximum likelihood estimate of the Weitzman's overlapping coefficient, which estimates the agreement of two densities. The proposed test statistic is derived in closed form. Simulated critical points are generated for the proposed test statistic for various sample sizes and significance levels via Monte Carlo Simulations. Statistical powers of the proposed test are computed via simulation studies and compared to those of the existing Log likelihood ratio test.     

The performance of alternative estimators for the probit model with first-order serial correlation 1

The purpose of the paper is to evaluate the relative performance of two generalized conditional moment (GCM) estimators in terms of their mean squared errors, for the Probit model with first-order serial correlation. The first estimator is a linearized one-step estimator described by Poirier and Ruud (1988). The second one is defined in the present paper. Monte Car10 experiments suggest that the GCM estimators outperform the ordinary Probit estimator. The two GCM estimators do almost equally well, except that the second one may be easier to calculate, especially in large samples.     

Shippers and freight operators perceptions of sustainable initiatives

The purpose of this paper is to document the extent to which Brazilian companies in retail channels have committed to adopting environmental sustainability measures, goals and strategies for waste disposal in the evaluation and planning of sustainable transportation. This paper also aims to examine the different viewpoints of sustainability issues and the preventive actions taken by companies in terms of controlling carbon dioxide emissions and proper disposal of tires, lubricant oils, accessories and spare parts. Finally, taking the perspective of these companies, this paper examines their difficulties in meeting environmental regulations. The research involved a survey completed by 185 representatives of different types of companies, including shippers (represented by manufacturers), LSPs (logistics service providers) and carriers. The non-linear canonical correlation was calculated to verify the opinions of these representatives from different companies regarding issues that impact on the environment, the preventive actions they adopt to reduce their environmental impact and their difficulties in meeting environmental regulations. The results show that shippers and LSPs have the same perceptions regarding these sustainability issues and preventive actions. In addition, the companies perceive high costs and the lack of training for their partners as the major challenges experienced in addressing these issues and undertaking preventive actions. Therefore they need to plan their transportation activities.     

Statistical estimation of internal available bandwidth

This paper presents a method for using end-to-end available bandwidth measurements in order to estimate available bandwidth on individual internal links. The basic approach is to use a power transform on the observed end-to-end measurements, model the result as a mixture of spatially correlated exponential random variables, carryout estimation by moment methods, then transform back to the original variables to get estimates and confidence intervals for the expected available bandwidth on each link. Because spatial dependence leads to certain parameter confounding, only upper bounds can be found reliably. Simulations with ns2 show that the method can work well and that the assumptions are approximately valid in the examples.     

The Complete Exact Null Distribution of Spearman's Rho for n = 12(1)18

Spearman's rank correlation coefficient, Rho, is a widely used nonparametric measure of association. Complete, exact tables of the null distribution are calculated and presented for n = 12 to 18.     

金融资产的动态非线性相关:一个新的模型

基于Kendall’sτ秩相关系数的优越性和定义,本文提出了新的具有明确经济意义的动态条件相关copula模型,将常用的Gaussian、Clayton和Gumbel函数统一根据该演化方程实现动态化,构造出三种Kendall’sτ动态条件相关copula模型,可用于刻画不同的相关模式。这些模型不仅参数少、容易估计,避免了现有动态条件相关copula模型构建方法各异导致的在实证中不利于比较的缺点,而且能够进行多步向前预测,有效地减少了进行样本外预测时的计算量,从而为刻画时变、非线性、非对称性和尾部相关等复杂的动态相关模式提供了新方法。     

Outlier detection in high-dimensional regression model

An outlier is defined as an observation that is significantly different from the others in its dataset. In high-dimensional regression analysis, datasets often contain a portion of outliers. It is important to identify and eliminate the outliers for fitting a model to a dataset. In this paper, a novel outlier detection method is proposed for high-dimensional regression problems. The leave-one-out idea is utilized to construct a novel outlier detection measure based on distance correlation, and then an outlier detection procedure is proposed. The proposed method enjoys several advantages. First, the outlier detection measure can be simply calculated, and the detection procedure works efficiently even for high-dimensional regression data. Moreover, it can deal with a general regression, which does not require specification of a linear regression model. Finally, simulation studies show that the proposed method behaves well for detecting outliers in high-dimensional regression model and performs better than some other competing methods.     

Robust bootstrap estimates in heteroscedastic semi-varying coefficient models and applications in analyzing Australia CPI data

This article deals with the estimation of the parametric component, which is of primary interest, in the heteroscedastic semi-varying coefficient models. Based on the bootstrap technique, we present a procedure for estimating the parameters, which can provide a reliable approximation to the asymptotic distribution of the profile least-square (PLS) estimator. Furthermore, a bootstrap-type estimator of covariance matrix is developed, which is proved to be a consistent estimator of the covariance matrix. Moreover, some simulation experiments are conducted to evaluate the finite sample performance for the proposed methodology. Finally, the Australia CPI dataset is analyzed to demonstrate the application of the methods.