The capacity of a committee

It is known that under moderate requirements of strategy - proofness, a committee is in general incapable of choosing by vote if the set of alternatives is too big. This led B. Peleg to introduce the notion of the capacity of a committee. It is shown here how this number is determined by the combinatorial structure of the committee. The general criteria are quite complex, but they are somewhat simplified by a homogeneity assumption, and they reduce to a simple arithmetical formula for symmetric committees.     

The Condorcet criterion and committee selection

Recent studies have evaluated election procedures on their propensity to select committees that meet a Condorcet criterion. The Condorcet criterion has been defined to use majority agreement from voters' preferences to compare the selected committee to all other committees. This study uses a different definition of the Condorcet criterion as defined on committees. The focus of the new definition is on candidates. That is, we consider majority agreement on each candidate in the selected committee as compared to each candidate not in the selected committee.This new definition of the Condorcet criterion allows for the existence of majority cycles on candidates within the selected committee. However, no candidate in the non-selected group is able to defeat any candidate in the selected committee by majority rule. Of particular interest is the likelihood that a committee meeting this Condorcet criterion exists. Attention is also given to the likelihood that various simple voting procedures will select a committee meeting this Condorcet criterion when one does exist.     

On characteristics of investment projects efficiency

The class of investment projects (named correct projects) and its efficiency characteristic (named limited profitability) is defined. Some properties of limited profitability showing its practical advantage are established. It is proved that limited profitability coincides with Arrow-Levhari characteristic. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Measuring the effects of M&As on Eurozone bank efficiency: an innovative approach on concentration and credibility impacts

Annals of Operations Research - The present paper examines the Mergers and Acquisitions’ (M&As’) effects on the European banking efficiency levels based on a sample of 43 listed...     

Measuring the impacts of production risk on technical efficiency: A state-contingent conditional order-m approach

This article studies the influence of risk on farms’ technical efficiency levels. The analysis extends the order-m efficiency scores approach proposed by Daraio and Simar (2005) to the state-contingent framework. The empirical application focuses on cross section data of Catalan specialized crop farms from the year 2011. Results suggest that accounting for production risks increases the technical performance. A 10% increase in output risk will result in a 2.5% increase in average firm technical performance.     

The selection efficiency of tournaments

We discuss tournaments in terms of their efficiency as probabilistic mechanisms that select high-quality alternatives (“players”) in a noisy environment. We characterize the selection efficiency of three such mechanisms – contests, binary elimination tournaments, and round-robin tournaments – depending on the shape of the distribution of players’ quality, the number of players, and noise level. The results have implications as to how, and under what circumstances, the efficiency of tournament-based selection can be manipulated.     

The interval efficiency based on the optimistic and pessimistic points of view

Data envelopment analysis (DEA) is a data-oriented approach for evaluating the performances of a set of peer entities called decision-making units (DMUs), whose performance is determined based on multiple measures. The traditional DEA, which is based on the concept of efficiency frontier (output frontier), determines the best efficiency score that can be assigned to each DMU. Based on these scores, DMUs are classified into DEA-efficient (optimistic efficient) or DEA-non-efficient (optimistic non-efficient) units, and the DEA-efficient DMUs determine the efficiency frontier. There is a comparable approach which uses the concept of inefficiency frontier (input frontier) for determining the worst relative efficiency score that can be assigned to each DMU. DMUs on the inefficiency frontier are specified as DEA-inefficient or pessimistic inefficient, and those that do not lie on the inefficient frontier, are declared to be DEA-non-inefficient or pessimistic non-inefficient. In this paper, we argue that both relative efficiencies should be considered simultaneously, and any approach that considers only one of them will be biased. For measuring the overall performance of the DMUs, we propose to integrate both efficiencies in the form of an interval, and we call the proposed DEA models for efficiency measurement the bounded DEA models. In this way, the efficiency interval provides the decision maker with all the possible values of efficiency, which reflect various perspectives. A numerical example is presented to illustrate the application of the proposed DEA models.     

The impact of operating environment on efficiency of public libraries

Central European Journal of Operations Research - Analysis of technical efficiency is an important tool in management of public libraries. We assess the efficiency of 4660 public municipal...     

The Shapley value without efficiency and additivity

We provide a new characterization of the Shapley value neither using the efficiency axiom nor the additivity axiom. In this characterization, efficiency is replaced by the gain-loss axiom (Einy and Haimanko, 2011), i.e., whenever the total worth generated does not change, a player can only gain at the expense of another one. Additivity and the equal treatment axiom are substituted by fairness (van den Brink, 2001) or differential marginality (Casajus, 2011), where the latter requires equal productivity differentials of two players to translate into equal payoff differentials. The third axiom of our characterization is the standard dummy player axiom.     

The efficiency of unidirectionally patrolled machines

This paper solves the problem of determining the efficiency of N (not identical) machines which are unidirectionally patrolled by one operative. Generally the machines will be equally spaced in a circular configuration so that the time to walk from one machine to the next will be a constant. However, the case of unequal spacing is just as easy to handle. It is assumed that breakdowns of machine j occur at random at average rate γ_j in running time, and that the time to repair this machine is a constant, c_j. This situation could arise from a mix of new and old machines or, in a textile context, in a situation where different types of yarn are being processed on different machines.     

The impacts of the full returns policy on a supply chain with information asymmetry

In contrast to the existing return policies literature assuming that information is symmetrical between the manufacturer and the retailer, we study the full returns policy’s impact on supply chains with information asymmetry. We first study the case that the base level of the demand follows a discrete distribution with two states. We find that the retailer benefits from the full returns policy in all circumstances, while the manufacturer and the supply chain are better off under some conditions. We then consider the situation in which the base level of the demand is a type of AR(1) process.     

The hyperbolic-oriented efficiency measure as a remedy to infeasibility of super efficiency models

The infeasibility problem in traditional super efficiency models has been well established. A generalization of traditional input- or output-oriented super efficiency models, the directional distance function also suffers from infeasibility and related problems. The hyperbolic-oriented efficiency measure provides an alternative to the input-oriented, output-oriented, and directional efficiency measures in super efficiency models and it has the distinct advantage of eliminating the infeasibility problem for positive input/output data. We also show that using a hyperbolic orientation in a super efficiency model allows us to find feasible solutions for certain cases when the requirement for all data to be positive is relaxed. Further we demonstrate the hyperbolic orientated super efficiency method in an outlier detection application. Together, these results establish the use of the hyperbolic orientation in super efficiency analysis as a realistic alternative in practice.     

The asymptotic efficiency of improved prediction intervals

We consider the Barndorff-Nielsen and Cox (1994, p. 319) method of modifying an estimative prediction interval to obtain an improved prediction interval with better conditional coverage properties. The parameter estimator, on which this improved interval is based, is assumed to have the same asymptotic distribution as the conditional maximum likelihood estimator. This improved interval depends strongly on the asymptotic conditional bias of this estimator, which can be very sensitive to small changes in this estimator. We show, however, that the asymptotic efficiency of this improved prediction interval does not depend on this bias.     

The weighted Russell measure of technical efficiency

Theoretical consideration of technical efficiency has existed since Koopmans [10] defined it for production possibilities for which it is not possible to increase any output without simultaneously increasing any input, ceteris paribus. The nonparametric approach to efficiency measurement known as Data Envelopment Analysis is based on the index of Farrell [9], which measures radial reduction in all inputs consistent with observed output. Even after Farrell efficiency is achieved, however, there may exist additional slack in individual inputs, suggesting that the Farrell index does not necessarily measure Koopmans inefficiency. To solve this problem, the non-radial Russell measure was introduced. This paper shows that problems may arise with the Russell measure due to restrictive assumptions on the implicit weighting of inputs and outputs. This paper develops a new measure, the Weighted Russell measure, that relaxes this assumption. Using simulated data, the new measure is shown to be preferred to existing methods. In addition, the new method is applied to analyze the performance of New York State school districts.     

Generalized interest rate dynamics and its impacts on finance and pensions

The recent global financial crisis caused implementation of negative or close to zero interest rates. This situation implies a necessity to study a flexible and simplistic model of interest rate, which well accommodates oscillations, cycles, and negative signs. In this article, we introduce a novel nonlinear stochastic interest rate model, which, as a special case, incorporates the standard linear model of Parker. Many practical implications for finance and pensions are obtained.     

The effect of competition on the efficiency of secondary schools in England

In this paper we calculate the technical efficiencies, based upon multiple outputs – school exam performance and attendance rates – of all secondary schools in England over the period 1993–1998. We then estimate models to examine the determinants of efficiency in a particular year, and the determinants of the change in efficiency over the period. Our results suggest that the greater the degree of competition between schools the more efficient they are. The strength of this effect has also increased over time which is consistent with the evolution of the quasi-market in secondary education. Competition is also found to be an important determinant of the change in efficiency over time. There is, however, some evidence of conditional convergence between schools.