“波特假说”的人力资本条件分析与检验

“波特假说”预言环境保护和经济发展可以实现双赢。研究认为,人力资本是实现环境友好型技术进步以及环境-经济综合绩效提升的支撑和匹配条件,亦即人力资本是“波特假说”成立的重要条件变量。实证结果显示:人力资本水平对环境-经济综合绩效存在直接的正向影响,且在东部和中部地区较为显著;全样本估计中环境规制对环境-经济综合绩效直接影响不显著,而人力资本可以改善环境规制的影响效应,间接作用于环境-经济综合绩效;进一步依据人力资本水平的分组检验,证实“波特假说”在人力资本水平较高地区的成立性,人力资本对环境-经济综合绩效的直接和间接影响均显著,验证了人力资本是“波特假说”成立条件这一分析结论。“新常态”下,应加强人力资本积累,健全人力资本流动机制,并依据地区人力资本条件科学实施环境规制,才能推动环境-经济综合绩效稳步提升。     

中国上市 ITO 企业经营效率评价及影响因素分析

运用基于规模报酬可变的投入导向的超效率DEA模型,对在沪深两市上市的具有代表性的30家中国ITO企业的经营效率进行实证研究,结果表明中国上市ITO公司整体运营效率不高,且各企业之间存在显著差异性。为分析企业规模、员工素质、研发投入等因素对中国上市ITO企业效率的影响,采用Tobit模型发现企业规模、员工素质、政府支持等因素对企业运营效率有着积极地影响,而研发投入对企业运营效率的影响并不显著。     

Inference in Semi‐Parametric Dynamic Models for Repeated Count Data

This paper deals with a longitudinal semi‐parametric regression model in a generalised linear model setup for repeated count data collected from a large number of independent individuals. To accommodate the longitudinal correlations, we consider a dynamic model for repeated counts which has decaying auto‐correlations as the time lag increases between the repeated responses. The semi‐parametric regression function involved in the model contains a specified regression function in some suitable time‐dependent covariates and a non‐parametric function in some other time‐dependent covariates. As far as the inference is concerned, because the non‐parametric function is of secondary interest, we estimate this function consistently using the independence assumption‐based well‐known quasi‐likelihood approach. Next, the proposed longitudinal correlation structure and the estimate of the non‐parametric function are used to develop a semi‐parametric generalised quasi‐likelihood approach for consistent and efficient estimation of the regression effects in the parametric regression function. The finite sample performance of the proposed estimation approach is examined through an intensive simulation study based on both large and small samples. Both balanced and unbalanced cluster sizes are incorporated in the simulation study. The asymptotic performances of the estimators are given. The estimation methodology is illustrated by reanalysing the well‐known health care utilisation data consisting of counts of yearly visits to a physician by 180 individuals for four years and several important primary and secondary covariates.     

灌装包装生产线效率评估系统的设计

针对国内一部分食品企业灌装包装生产线难以量化生产线效率的现状,提出了一套切实有效的生产线效率评估系统。通过评估设备速度V-曲线,以现代信息化技术为基础,提取出关键设备的停机记录,其中包含了停机的起始时间、终止时间、时长、分类、机台和原因等几大关键项内容,然后对内外部因素造成的各类时间损失进行准确量化评估,从而构建以总资产利用率、线毛产出率、设备综合利用率和线效率4项指标为衡量标准的一套生产线效率评估系统。本系统实现了灌装包装生产线数字化过程,整体透视出企业的综合管理能力、部门之间的协调配合能力、设备运行能力和故障处理能力。基于此数字化效率评估系统,可以分析停机成因,识别出影响生产线效率的核心要素,通过针对性的优化手段,达到提高效率的目的,实现降低成本和提高利润的业务目标。     

我国粮食生产的环境技术效率测度

采用方向距离函数和Kernel密度估计方法,对1992—2012年中国29个省（市、区）的粮食生产环境技术效率进行了测度和分析,以考察城镇化和工业化加速时期中国各省份以及各粮食生产功能区粮食生产与资源环境的协调情况。研究结果表明：（1）全国及各粮食生产功能区粮食生产环境状况总体上呈现出逐渐恶化现象,其中,粮食主产区优于粮食主销区,粮食主销区优于粮食平衡区;（2）中国各省份粮食生产环境技术效率存在明显的非均衡性;（3）总体而言,我国粮食生产环境技术效率的地区差距在逐渐扩大,呈现出两级分布, 但是在各个粮食生产功能区形势有所不同。     

Empirical Likelihood for the Additive Hazards Model with Current Status Data

We investigate empirical likelihood for the additive hazards model with current status data. An empirical log-likelihood ratio for a vector or subvector of regression parameters is defined and its limiting distribution is shown to be a standard chi-squared distribution. The proposed inference procedure enables us to make empirical likelihood-based inference for the regression parameters. Finite sample performance of the proposed method is assessed in simulation studies to compare with that of a normal approximation method, it shows that the empirical likelihood method provides more accurate inference than the normal approximation method. A real data example is used for illustration.     

Estimation of Population Variance from Multi-ranker Ranked Set Sampling Designs

In this article, we develop an estimator for a population variance based on a multi-ranker ranked set sampling design. In a multi-ranker design, the units are ranked by more than one ranker allowing ties whenever the confidence level of the rankers is low. The ranking information of all rankers is then combined in a meaningful way to create a single measure. This measure is used to construct the sampling design and a new estimator for the population variance. The article investigates the bias and relative efficiency of the proposed variance estimator. It is shown that the new estimator performs as good as or better than its competitors in the literature.     

On the Joint Estimation of Heterogeneous Technologies,Technical, and Allocative Inefficiency

In this article, we provide a semiparametric approach to the joint measurement of technical and allocative inefficiency in a way that the internal consistency of the specification of allocative errors in the objective function (e.g., cost function) and the derivative equations (e.g., share or input demand functions) is assured. We start from the Cobb–Douglas production and shadow cost system. We show that the shadow cost system has a closed-form likelihood function contrary to what was previously thought. In turn, we use the method of local maximum likelihood applied to a system of equations to obtain firm-specific parameter estimates (which reveal heterogeneity in production) as well as measures of technical and allocative inefficiency and its cost. We illustrate its practical application using data on U.S. electric utilities.     

能效标识对节能产品选择的引导效用分析——基于京东家电线上销售的实证检验

搜集冰箱、洗衣机、空调三种大家电的线上销售数据,通过描述性分析、组间差异比较、多元回归分析等方式分析能效标识的市场引导效果。结果显示消费者对不同等级家电产品的选择量存在差异,但不同能效等级间消费者满意度并无明显差异,能效等级并非是影响消费者选择和满意度的显著因素。     

基于出行者选择的城市公交和共享单车竞合关系影响因素研究

摘要:为了更好地便利交通并促进城市地面交通系统可持续发展,基于出行者行为选择,从竞合关系视角研究共享单车对公交的影响,以共享单车对公交影响的相关文献为案例进行研究,包括北美、欧洲、大洋洲和亚洲的城市,并总结归纳相关影响因素;对北京市出行者进行了SP问卷调查,利用MNL模型定量分析了各种因素对出行者公交、共享单车选择的影响,采用二元logit模型估计组合模式选择的影响机制。研究认为,共享单车作为独立个体或接驳公共交通的新模式,与地面公交交通模式间竞争与合作并存,可骑行距离、道路基础设施以及出行者的心理因素都会导致共享单车和公交之间的竞争;相反,公交换乘站之间的距离、出行端点与站点的间距均会影响二者的合作模式。城市交通管理者应合理配置公交和共享单车的数量,鼓励市区出行者根据自己的需求选择不同的出行模式以快速接驳轨道交通,提倡竞争性并行,促进公交和共享单车在综合交通系统中的合作与协调发展。