Ensuring units invariant slack selection in radial data envelopment analysis models,and incorporating slacks into an overall efficiency score

This paper introduces a new methodology ensuring units invariant slack selection in radial DEA models and incorporating the slacks into an overall efficiency score. The CCR and BCC models are units invariant in their radial component, but not in their slack component, thus changing the units of measurement of one or more variables can change the models' solution. The proposed Full Proportional Slack (FPS) methodology improves the slack selections of the CCR and BCC models by producing slack selections that (a) are units invariant, thus producing fully units invariant models, (b) maximize the relative improvements represented by the slacks, and not their values, and (c) measure the full slacks that need to be removed from their corresponding variables. The FPS methodology is a fully oriented methodology first maximizing the improvements in the variables on the side of the orientation of the model. The Proportional Slack Adjusted (PSA) methodology incorporates the FPS slacks into an overall efficiency score, making it easier to interpret and use the results. The FPS and PSA methodologies are illustrated using an input oriented VRS Loan Quality DEA model with data from the retail branch network of one of Canada's largest banks.     

Measuring unemployment

The forecasts and assumptions of government and business regarding availability of labour are based in part on official statistics has been a matter of considerable debate in recent years. In this paper the author presents his views on the interpretation of the relevant U.K. statistics.     

Minimizing makespan in an ordered flow shop with?machine-dependent processing times

We consider a generalization of the proportionate flow shop problem with the makespan objective. Each job has a processing requirement and each machine has a characteristic value. In our case, we assume that the time a job occupies a machine is equal to the processing requirement of the job plus a setup time that is equal to the characteristic value of that machine. In this paper, we consider permutation schedules and show that the problem is solvable in polynomial time when the number of machines is fixed.     

Union militancy among public employees: A public choice hypothesis

Public employee union membership has grown from under 6 percent to over 20 percent of all union members since 1963. This growth has been ascribed to lagging wages, inelastic demands for public products, political clout, changed laws, and reduced professionalism and public spiritedness. These explanations agree that public employees now confront their employers in a newly militant and adversarial mode. We disagree. We model this growth in membership as a continuation of old public employment relations and forecast the soon diminution of militancy.     

A Non-parametric Test for Generalized First-order Autoregressive Models

We derive a non-parametric test for testing the presence of V(X_i,ε_i) in the non-parametric first-order autoregressive model X_i+1=T(X_i)+V(X_i,ε_i)+U(X_i)ε_i+1, where the function T(x) is assumed known. The test is constructed as a functional of a basic process for which we establish a weak invariance principle, under the null hypothesis and under stationarity and mixing assumptions. Bounds for the local and non-local powers are provided under a condition which ensures that the power tends to one as the sample size tends to infinity.The testing procedure can be applied, e.g. to bilinear models, ARCH models, EXPAR models and to some other uncommon models. Our results confirm the robustness of the test constructed in Ngatchou Wandji (1995) and in Diebolt & Ngatchou Wandji (1995).     

Nonverbal expectancy violations and conversational involvement

A central feature of nonverbal expectancy violations theory is that unexpected behaviors trigger a cognitive-affective appraisal of such behavior, leading to a valencing of the behavior(s) as positive or negative. It has been proposed that communicator reward mediates the interpretation and evaluation of such violations but may be more important when the violative act is ambiguous in meaning than when it is not. Unclear is whether nonverbal behavioral composites introduce greater or less equivocality of interpretation. Two experiments employing multi-cue conversational involvement violations addressed this issue. In the first, dyads (N=51) engaged in a 10-minute baseline interview, after which participants rated each other on several measures of reward valence. One randomly selected member then served as a confederate interviewee during a second interview and either significantly increased or decreased involvement. In the second experiment, reward was manipulated as physical attractiveness, status, and task expertise. Dyads (N = 60) engaged in prolonged problem-solving discussions during which the confederates either committed an involvement violation or not. In both experiments, the involvement changes were sufficiently unexpected, arousing, and distracting to qualify as violations of expectations. Analysis of message interpretations indicated that (1) relative to normal involvement levels, increased nonverbal involvement was interpreted as most immediate/affectionate, receptive, similar, dominant, and composed, and decreased involvement as least so, and (2) reward mediated only the interpretation of formality. High involvement violations in turn produced greater attraction, credibility, and persuasiveness than low involvement violations for high as well as low-reward communicators, as predicted.where Joe Walther and Jim Baesler are doctoral students. An earlier version of this paper was presented to the annual meeting of the International Communication Association, New Orleans, May 1988.     

The Persistence of Outmoded Contraceptive Regimes: The Cases of Mexico and Brazil

Two of the most striking characteristics of contraceptive practice in the world today are the wide variation in patterns of use across countries and the tendency of the distribution of use by method to persist or narrow, even as new methods become available. The argument advanced in this article is that the disposition to commit to a reduced range of methods results from positive feedback in the process of contraceptive choice, and follows the logic of path dependence. The positive feedback derives, in large part, from social interaction among both the providers and the users of contraceptive methods. The persistence of outmoded contraceptive regimes is illustrated with the experience of Mexico and Brazil. In each case, it is argued that the conditions, events, and policies in the early stage of the adoption process have had a determinant bearing on the contraceptive practice prevailing in the late 1990s.     

Optimal Bayesian Randomization

Randomization is a puzzle for Bayesians. The intuitive need for randomization is clear, but there is a standard result that Bayesians need not randomize. In this paper we propose a model in which randomization is a strictly optimal procedure. The most important aspect of our model is that there are several parties who make different decisions and observe different data. The result also sheds light on the ethical considerations involving randomization in a clinical trial.