On efficiency of the ratio estimator

Summary The exact mean square error for the ratio estimator of a finite population total based on simple random sampling without replacement is shown to have an expected value less than that of the variance of the ratio estimator based on Midzuno’s scheme, under a usual super-population model.     

Progressive stress accelerated life tests under finite mixture models

In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low, the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained. A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision of the MLEs and to obtain confidence intervals for the parameters involved.     

Finding Closest Targets in Non-Oriented DEA Models: The Case of Convex and Non-Convex Technologies

This paper draws attention for the fact that traditional Data Envelopment Analysis (DEA) models do not provide the closest possible targets (or peers) to inefficient units, and presents a procedure to obtain such targets.It focuses on non-oriented efficiency measures (which assume that production units are able to control, and thus change, inputs and outputs simultaneously) both measured in relation to a Free Disposal Hull (FDH) technology and in relation to a convex technology. The approaches developed for finding close targets are applied to a sample of Portuguese bank branches.     

长沙市地下管线测量数字化的更新、软件升级及应用

地下管线的主要特点是隐蔽性,地下分布纵横交错,年代已久的原有手工数据几乎无参考价值且存档不便、使用复杂、工作量大。使用自主开发升级后的计算机程序软件,不仅可以大大提高地下管线测量数据的更新、规划设计及施工的效率,而且可以通过CAD图形分析对特殊地段重要管线是否保留利用作出决定。     

Productive Efficiency of the Swine Industry in Hawaii: Stochastic Frontier vs. Data Envelopment Analysis

Improving productive efficiency is an increasingly important determinant of the future of the swine industry in Hawaii. This paper examines the productive efficiency of a sample of swine producers in Hawaii by estimating a stochastic frontier production function and the constant returns to scale (CRS) and variable returns to scale (VRS) output-oriented DEA models. The technical efficiency estimates obtained from the two frontier techniques are compared. The scale properties are also examined under the two approaches. The industry's potential for increasing production through improved efficiency is also discussed.     

An Average Derivative Estimation of Stochastic Frontiers

This paper utilizes the average derivative estimation of Stoker (1986) and the pesudo-likelihood estimation of Fan, Li, and Weersink (1996) to estimate a semiparametric stochastic frontier regression, y = g(x) + , where the function g(.)is unknown and is a composite error in a standard setting. The proposed semiparametric method of estimation is applied to data on farmers' credit unions in Taiwan. Empirical results show that the banking services of the farmers' credit unions is subject to economies of scale, but high degree of cost inefficiency in operation.     

基于自组织理论的我国资本市场效率的重新审视

效率是资本市场的核心问题,不同的学者从不同的方面对这一问题进行了研究。本文另辟新径,从自组织角度对资本市场运行过程中产生的熵增、序参量和涨落机制进行了研究;并有针对性地提出一系列改革措施,以期实现资本市场效率的帕累托改进,促进经济和社会的和谐可持续发展。     

《萨班斯法案》孰是孰非:基于成本与效率(收益)的分析视角

《萨班斯法案》的出台堪称注册会计师行业的一件大事，从理论上看，该法案各项条款的出台确实具有积极的意义，但仍然存在缺陷，它更多地强调监管的作用，而监管的效率往往不如制衡的效率；它更多地强调经济处罚和刑事处罚的作用，而这两种处罚却必须以民事赔偿为前提，并最终使作假行为的作假成本大大高于作假收益。     

江西大型企业资本运作模式的现状及其改进对策研究

资本运作是一种有效配置资源、实现企业资本增殖的活动,其核心是产权制度创新。本文对江西大型企业资本运作模式的现状进行了分析,进而提出了一系列的合理的改进对策,以期提高起运作绩效。     

A two-stage stratified Warner’s randomized response model using optimal allocation

This paper applies Kim and Wardes (2004) stratified Warners randomized response model to Mangat and Singhs (1990) two-stage randomized response model. The proposed stratified randomized response model has an optimal allocation and a large gain in precision. Hence, the estimator based on the proposed method is more efficient than Kim and Wardes (2004) and Mangat and Singhs (1990) estimators under the conditions presented in both the case of completely truthful reporting and that of not completely truthful reporting by the respondents.