New Models for Data Envelopment Analysis. Measuring Efficiency Outwith the VRS Frontier

Some models are presented in this paper which extend the concept of measuring superefficiency to the useful case of variable returns-to-scales (VRS), thus enabling the ranking of efficient as well as inefficient units. Two models, namely the Universal Radial Model and the Universal Additive Model, are presented that also have strong invariance properties (units and translation invariance). For both of these models a method for normalising the efficiency scores on a (0-1+) scale is presented. These models have been implemented in a software package and applied to the ranking of units in an industrial context.Data envelopment analysis (DEA), Superefficiency, Universal models

Data Envelopment Analysis Models of Investment Funds

Publisher PD

Performance evaluation of ethical mutual funds in slump periods

In this paper we tackle the problem of the presence of negative average rate of returns in the computation of the performance of ethical mutual funds. The presence of these negative values raises problems both in the computation of the classical performance indicators and in DEA modeling. In this paper we propose a suitably adjusted DEA model which allows the presence of non negative outputs. The model is applied to data on the UK market of ethical mutual funds.Performance evaluation, ethical mutual funds, data envelopment analysis

DEA models for ethical and non ethical mutual funds with negative data

This paper tackles the problem of the presence of negative average rates of returns in the evaluation of the performance of mutual funds using a DEA approach. We present some extensions of DEA models for the evaluation of the performance of mutual funds that enable to compute the performance measure also in the presence of negative rates of returns. These extensions regard a model that can be used for investments in mutual funds which have profitability as main objective and two models specifically formulated for ethical mutual funds that include also the ethical objective among the outputs and differ in the way the ethical goal is pursued by investors. The models proposed are applied to the European market of ethical mutual funds. In order to do so, a measure of the ethical level which takes into account the main socially responsible features of each fund is built.

Dealing with Interval Scale Data in Data Envelopment Analysis

This papaer considers the problem of interval scale data in the most widely used models of Data Envelopment Analysis (DEA), the CCR, and the BCC models. Radial models require inputs and outputs measured on the ratio scale. Our focus is on how to deal with interval scale variables especially when the interval scale variable is a difference of two ratio scale variables like profit or the decrease/increase in bank accounts. Using these ratio scale variables as variables in the DEA model we suggest radial models. An approach to how to deal with interval scale variables when we relax the radiality assumption is also discussed

Minimal D=4 supergravity from the superMaxwell algebra

We show that the first-order D=4, N=1 pure supergravity lagrangian four-form can be obtained geometrically as a quadratic expression in the curvatures of the Maxwell superalgebra. This is achieved by noticing that the relative coefficient between the two terms of the Lagrangian that makes the action locally supersymmetric also determines trivial field equations for the gauge fields associated with the extra generators of the Maxwell superalgebra. Along the way, a convenient geometric procedure to check the local supersymmetry of a class of lagrangians is developed.Comment: Plain latex, 14 pages. Two misprints corrected, one reference adde

Negative Data in DEA: A Simple Proportional Distance Function Approach

The need to adapt Data Development Analysis (DEA) and other frontier models in the context of negative data has been a rather neglected issue in the literature. Silva Portela, Thanassoulis, and Simpson (2004) proposed a variation on the directional distance function, a very general distance function that is dual to the profit function, to accomodate eventual negative data. In this contribution, we suggest a simple varaiation on the proportional distance funtion that can do the same job.DEA, negative data, directional distance funtion

Efficiency analysis of Policies against desertification by applying DEA: a case study in the river Guadalentin catchment (Almeria, Spain)

This paper deals about an attempt to evaluate the different policies against desertification carried out during a twenty five year period (1978-2003) in the eight municipalities which compound the river Guadalentín catchment (Murcia, Spain). The approach is based on DEA and the European Environmental Agency indicator studies, the former to measure the efficiency and the second to select the best environmental indicators. The analysis has been reiterated with three different sets of outputs related to the different levels and aspects of the desertification process- from the merely soil losses to the overall desertification process in which population losses are considered. As a result a set of efficiency indexes has been obtained for each municipality, which show clearly the contribution of each action against desertification. These results are very valuable to establish future long term desertification policies in similar territories

On constructing a composite indicator with multiplicative aggregation and the avoidance of zero weights in DEA

Peer reviewe

A translation invariant pure DEA model

YesThis communication complements the DEA model proposed by Lovell and Pastor (1999), by incorporating both positive and negative criteria in the model. As such, we propose a DEA model, known as pure DEA, using a directional distance function approach