Robust Smoothed Rank Estimation Methods for Accelerated Failure Time Model Allowing Clusters

Smoothed Gehan rank estimation methods are widely used in accelerated failure time (AFT) models with/without clusters. However, most methods are sensitive to outliers in the covariates. In order to solve this problem, we propose robust approaches based on the smoothed Gehan rank estimation methods for the AFT model, allowing for clusters by employing two different weight functions. Simulation studies show that the proposed methods outperform existing smoothed rank estimation methods regarding their biases and standard deviations when there are outliers in the covariates. The proposed methods are also applied to a real dataset from the “Major cardiovascular interventions” study.     

Comparison of hazard rates for dependent random variables

In this paper, we define and study a new notion for the comparison of the hazard rates of two random variables taking into account their mutual dependence. Properties, applications and the comparison for a data set are given.     

Understanding Estimators of Treatment Effects in Regression Discontinuity Designs

In this paper, we propose two new estimators of treatment effects in regression discontinuity designs. These estimators can aid understanding of the existing estimators such as the local polynomial estimator and the partially linear estimator. The first estimator is the partially polynomial estimator which extends the partially linear estimator by further incorporating derivative differences of the conditional mean of the outcome on the two sides of the discontinuity point. This estimator is related to the local polynomial estimator by a relocalization effect. Unlike the partially linear estimator, this estimator can achieve the optimal rate of convergence even under broader regularity conditions. The second estimator is an instrumental variable estimator in the fuzzy design. This estimator will reduce to the local polynomial estimator if higher order endogeneities are neglected. We study the asymptotic properties of these two estimators and conduct simulation studies to confirm the theoretical analysis.     

Influence diagnostics for the Weibull-Negative-Binomial regression model with cure rate under latent failure causes

In this paper, we propose a flexible cure rate survival model by assuming that the number of competing causes of the event of interest follows the Negative Binomial distribution and the time to event follows a Weibull distribution. Indeed, we introduce the Weibull-Negative-Binomial (WNB) distribution, which can be used in order to model survival data when the hazard rate function is increasing, decreasing and some non-monotonous shaped. Another advantage of the proposed model is that it has some distributions commonly used in lifetime analysis as particular cases. Moreover, the proposed model includes as special cases some of the well-know cure rate models discussed in the literature. We consider a frequentist analysis for parameter estimation of a WNB model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes and present some ways to perform global influence analysis. Finally, the methodology is illustrated on a medical data.     

中国农村民间借贷市场融资约束环境下利率定价模型分析——以广东农村实地调查数据为例

通过对广东农户民间借贷行为实地调查的问卷进行数据分析,了解农村民间借贷中的资金供求关系,发现存在的融资约束问题,进而对融资约束环境下民间借贷资金利率定价过程进行实证分析;着重考察农村民间借贷利率受公共信息和私人信息影响的程度,从借款人和贷款人的角度分别建立定价模型进行经验分析。结果显示,定价模型在F检验1%水平上显著,其他模型具有R2的统计显著性;反映借款用途的变量在10%水平上显著,其他变量均在5%水平上显著。这说明该市场利率能够反映公共信息的影响,借款人和贷款人的利率定价也反映了各自私人信息中相关风险和财务能力因素的影响,得到的经验结论主要是:第一,农村民间借贷市场是自主交易的金融市场;第二,其利率定价过程基本市场化。     

商业银行利率选择与信贷配给问题研究

目前我国经济高速发展,但融资难的问题一直阻碍中小企业的进一步发展,这是多方原因造成的.其中长期存在于信贷市场中的信贷配给(credit rationing)现象、银行利率选择问题一直为国内学术界所关注,但是对于形成信贷配给的银行与企业的决策过程关注得不多.笔者从传统的信贷市场均衡入手,着重分析了信贷市场的利率选择、最优利率形成原则以及信贷配给产生的原因,以期对我国进行宏观经济调整起到一定的借鉴作用.     

上市公司债务重组财务效应研究

债务重组是很多企业在生产经营活动中遇到的重大问题,债务重组的结果如何,会对企业产生重大影响。在分析了中国深圳和上海证券交易所的上市公司的债务重组的相关数据之后,得出了债务重组能够显著改善企业业绩的相关结论,提出了要加强对债务重组信息披露等相关建议。     

关于高校就业率的思考

高校就业率政策在激发高校提高办学质量、重视就业指导工作等方面起着积极的作用。随着我国教育体制改革的深入,高等教育由精英化向大众化转变,大学生就业问题逐渐成为社会关注焦点之一,高校毕业生就业率也日益受到重视。针对目前就业率评价与统计过程中出现的问题,提出理性地看待高校就业率就要合理设置统计时间、科学界定就业率统计途径、结合就业率与就业质量来评价高校就业情况。     

珠三角地区企业员工满意度及离职意愿的探讨

员工的自愿离职直接影响到企业人才的稳定性,也会增加企业的人力资源成本。员工的实际离职产生于离职意愿,而离职意愿与员工满意度密切相关。了解员工对工作的态度,将有助于我们制定相应的人力资源管理的措施,更好地留住企业所需的人才,增强企业的竞争力。文章采取问卷调查的方法,通过方便随机抽样获得1469份有效问卷,被试者来自珠三角地区不同企业的员工。研究内容主要包括:广东珠三角地区的企业员工工作满意度和构成因素,员工离职意愿,人口特征对满意度、离职意愿、工作积极性的影响。     

基于人民币升值的船舶出口业影响研究

在各种主客观因素的作用下,人民币汇率制度改革应运而生,这一汇率变化必将对中国的社会和经济带来巨大的影响。近年来,我国的船舶出口业发展喜人,在国际市场上拥有很强的竞争力,并有着继续壮大的趋势,但随着人民币升值的影响以及船舶出口业的特点,决定了船舶出口业必定要受到较大的冲击和影响。所以在整个贸易大环境下,船舶出口业只有清楚地认识到人民币升值带来的影响,才能正确把握船舶出口的前进方向,运用有效的措施来巩固并促进船舶出口业的发展。