Optimizing multi-stage production with constant lot size and varying numbers of batches

The model presented in this paper assumes that a uniform lot size is produced through a series of manufacturing stages, with a single set-up and without interruption at each stage. Transportation of partial lots, called batches, is allowed between stages after the whole batch is completed. The batch sizes must be equal at any particular stage, but the optimal number of equal-sized batches may differ across stages. Of course, the set-up costs, the inventory-holding costs and the transportation costs influence both the optimal batch-sizes at the various stages and the uniform lot size. An optimization method for this deterministic model is developed and is illustrated by an example.     

Computer-based scheduling of technical resources

This paper considers the design of a Scheduling Sub-System which could be attached to an existing computerised data processing system in order to enhance its overall operation. It draws heavily on the experience of the authors in designing a system to assist in the scheduling of video tape machines within BBC Television.     

New Lilliefors and Srinivasan tables with applications

Two approaches to the problem of goodness-of-fit with nuisance parameters are presented in this paper, both based on modifications of the Kolmogorov-Smirnov statistics. Improved tables of critical values originally computed by Lilliefors and Srinivasan are presented in the normal and exponential cases. Also given are tables for the uniform case, normal with known mean and normal with known variance. All tables were computed using Monte Carlo simulation with sample size n = 20000.     

A Taxometric Analysis of Problem Gambling Data from a South African National Urban Sample

We investigate the question whether problem gambling (PG) in a recent South African sample, as measured by the Problem Gambling Severity Index (PGSI), is dimensional or categorical. We use two taxometric procedures, Mean Above Minus Below A Cut (MAMBAC) and Maxim Covariance (MAXCOV), to investigate the taxonic structure of PG as constructed by the PGSI. Data are from the 2010 South African National Urban Prevalence Study of Gambling Behavior. A representative sample of the urban adult population in South Africa (N = 3,000). Responses are to the 9 item PGSI. MAMBAC provided positive but modest evidence that PG as measured by the PGSI was taxonic. MAXCOV pointed more strongly to the same conclusion. These analyses also provide evidence that a PGSI cutoff score of 10 rather than the standard 8 may be called for. PG as constructed by the PGSI may best be thought of as categorical, but further studies with more theory based measurements are needed to determine whether this holds in a wider range of samples and for other screens. A higher cutoff score may be called for on the PGSI when it is used for research purposes to avoid false positives.     

Enterprising Education: Doing Away with the Public School System

We critically examine the accepted notion that primary education is a legitimate and necessary function of the state. The notion is based upon three tenets: 1) public education is a necessary condition for democracy, 2) the market will not provide equal access and quality of education to all, and 3) education represents an external economy. Each tenet is addressed and evaluated according to its merits. In doing so, we also contrast the fulfillment of the ends implicit in the tenets under state and market provisions. We conclude that the state provision of primary education cannot be justified by these goals, and that market provision is a preferable alternative. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Determinants of Management Development: The Views of MBA Graduates

This article is derived from survey data obtained from a structured sample of 450 MBA graduates and is part of a wider programme of research investigating the current state of management development in Britain. The intention is to analyse the determinants of the amount, the methods and the impact of management development systems in UK organizations and to assess these findings in relation to a comparable analysis of HRD managers. Both the amount and the variety of management development methods are greater than has been previously reported and, for the HRD sample, the impact of this activity is broadly positive. While agreeing on the amount, MBA managers are less enthusiastic about the availability and effectiveness of management development they have experienced. Overall, the management development policy choices made by organizations are consistently the most influential in determining outcomes, and the implications for this are discussed.     

Union wage differentials for covered members and nonmembers in Great Britain

I present the first longitudinal estimates of covered union member and covered nonmember wage differentials in Great Britain. Crosssectional estimates show that covered union members receive a premium of about 10 percent over other workers, but covered nonmembers have no significant wage differential. Longitudinal estimates that accounted for fixed effects, selectivity, and measurement error indicated that OLS estimates are downward biased. The “true” union wage differential is likely about 30–35 percent. There is a large negative selection effect to union membership. No robust estimate could be found for covered nonmembers. This paper has benefited from conversations with Martyn Andrews, Wiji Arulampalam, Alison Booth, Tim Hatton, John Hutton, George Jakubson, Costas Meghir, and Andrew Oswald. Alison Booth kindly made extensive comments on an earlier draft, which greatly improved the exposition. John Budd, Hank Farber, and Larry Katz directed me towards related work in the U.S. I am also grateful to seminar participants at the University of York University of Essex, and the CEPR Workshop on Labour Market Issues. Thanks to the ESRC Data Archive for supplying the Family Expenditure Survey (FES) data. All data, computer programs, and results alluded to in the text are available on request. The British Household Panel Study (BHPS) and FES data are available from the ESRC Data Archive at the University of Essex. The Panel Study of Manufacturing Establishments (PSME) data are available from the author on request.     

Reconnecting Past,Present and Future Lives: Therapy with a Young Person who Experienced Severe Childhood Privation

This case study describes therapy over a three year period with a young adopted person who presented as highly suicidal, with a childhood background characterised by severe privation and abuse. The paper describes the use of a visual Life line, designed to assist the young person in reconnecting and honouring different parts of her life. A flexible and client centred therapeutic approach is also described.