On the Role of Weight Restrictions in Data Envelopment Analysis

This paper examines the role that weight restrictions play in Data Envelopment Analysis (DEA). It is argued that the decision to include a factor (input or output) in a DEA model represents an implicit judgement that the factor has a non-trivial weight. It therefore seems perverse to allow DEA to assign a trivial weight to that factor in assessing the efficiency of a unit. There is therefore a strong case for imposing restrictions on factor weights. However, many existing methods of weight restriction are in practice unwieldy. This paper proposes an alternative approach we term contingent weight restriction which is both practical and intellectually consistent with the DEA philosophy. The paper explores the implications of alternative methods of weight restriction using simulated data from a well known production process.     

The Performance of Actively Managed International Mutual Funds

International mutual funds allow individual investors to diversify abroad at a reasonable cost. This paper tests whether international funds that actively engage in country and security selection outperform passive global benchmarks. We apply a mean-variance efficiency test that incorporates the practical prohibition against short sales of open-end mutual funds. Our tests reject the efficiency of the world equity market portfolio over the sample period, and our funds as a group outperform the inefficient world index. However, we find no evidence of security selectivity ability using a 12-country benchmark. We do find that active international funds provide global diversification benefits. Tests using the Positive Period Weight (PPW) measure of Grinblatt and Titman (1989), which is robust to nonlinearity in fund and benchmark returns, yield similar results.     

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.     

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。     

The Measurement of Consumption Efficiency Considering the Discrete Choice of Consumers

In this study we propose a mathematical definition of the consumption efficiency of multi-attribute products in the price–quality space. A new model, the discrete Range Adjusted Measure (RAM) model, is suggested as an empirical tool to measure the level of consumption efficiency. We further discuss the effect of consumption efficiency on the innovation incentive. Empirical work is made for the mobile phone market. We expect that the consumption efficiency concept will contribute to the extension of the traditional framework of production efficiency analysis on the one hand and to the understanding of the nature of innovation in a technology-intensive market on the other hand.JEL Classification: C67, D11, D12, D21