Weekly scheduling models for traveling therapists

This paper presents a series of models that can be used to find weekly schedules for therapists who provide ongoing treatment to patients throughout a geographical region. In all cases, patient-appointment times and visit days are known prior to the beginning of the planning horizon. Variations in the models include single vs. multiple home bases, homogeneous vs. heterogeneous therapists, lunch break requirements, and a nonlinear cost structure for mileage reimbursement and overtime. The single home base and homogeneous therapist cases proved to be easy to solve and so were not thoroughly investigated. This left two cases of interest: the first included only lunch breaks while the second added nonlinear overtime and mileage reimbursement costs. For the first case, 40 data sets were solved, each consisting of either 15 or 20 therapists and between roughly 300 and 540 patient visits over five days. For each instance, we were able to obtain the minimum cost of providing residential healthcare services using a commercial solver. The results showed that CPU time increases more rapidly than total cost as the total number of visits grows. For the second case, which was much more difficult, it was necessary to develop heuristics to find good solutions quickly. Results for 5- through 20-therapist instances are presented and compared to the linear programming relaxation lower bounds. In the first of two parametric analyses, the tradeoff between the number of therapists on staff and the cost of providing service was examined. In the second, a similar tradeoff was explored between cost can the number of home bases used by the therapists.     

Working sick and out of sorts: a cross-cultural approach on presenteeism climate,organizational justice and work–family conflict*

Abstract

A climate of presenteeism has important effects on employee well-being and the organization itself. Our study, based on surveys of health sector employees in six different countries (Brazil, Ecuador, Lebanon, Portugal, Russia and Spain) examines whether organizational justice plays a mediating role in the relationship between a presenteeism climate in the organization and work–family conflict (WFC). Our results indicate that the perception of organizational justice and the presenteeism climate do influence WFC. Moreover, higher levels of WFC were found in non-Latin countries. This study contributes to the work attendance and life balance field by providing cross-cultural empirical evidence corroborating the effect of justice and presenteeism climate on the WFC.     

Rules,rogues, and risk assessors: Academic responses to Enron and other accounting scandals

Abstract

The recent accounting scandals in the USA and the resulting regulation of the US profession via the Sarbanes–Oxley Act have led to the resurrection of an old debate: principles vs. rules. We argue that such a debate is jejune and serves as little more than a diversion from discussing more substantive issues raised by events like Enron and Andersen. Accounting is not confronted by a choice of principles to the exclusion of rules or vice versa. Principles underlie any set of rules, and any implementation of principles will inevitably involve adopting some rules. We take issue with various analyses of the accounting scandals that rely too exclusively on the principles of neo-classical economics. We conclude by identifying four major obstacles impeding meaningful academic and educational treatment of the maladies of which Enron is merely a symptom.     

SEMIPARAMETRIC VECTOR MEM

Financial time series are often non‐negative‐valued (volumes, trades, durations, realized volatility, daily range) and exhibit clustering. When joint dynamics is of interest, the vector multiplicative error model (vMEM; the element‐by‐element product of a vector of conditionally autoregressive scale factors and a multivariate i.i.d. innovation process) is a suitable strategy. Its parameters can be estimated by generalized method of moments, bypassing the problem of specifying a multivariate distribution for the errors. Simulated results show the gains in efficiency relative to an equation‐by‐equation approach. A vMEM on several measures of volatility justifies a joint approach revealing full interdependence. Copyright © 2012 John Wiley & Sons, Ltd.     

The economics of markets and platforms

Advances in the study of both markets and platforms contribute to economics. Platforms are typically digital markets, although platforms can designate markets generally. So, the economics of markets and the economics of platforms are one and the same. Platforms show the critical role of intermediaries in endogenous price adjustment and market clearing. The platform model remedies problems with general equilibrium analysis by combining and extending the basic Walrasian and Marshalian market models. The analysis of platforms provides explanations for the bid–ask spread, including market power, search costs, matching costs, adverse selection, and moral hazard. The study of platforms demonstrates the importance of participation and coordination in the formation of markets. The discussion emphasizes that platforms have significant implications for the theory of the firm. The analysis further considers how platforms affect innovation and entrepreneurship.     

Supply management in American public administration: Towards an academic discipline?

This article examines the development of supply management in the U.S. to assess its progress towards academic disciplinary status. A comparison of the fields of business administration and public administration indicates that supply management is more developed in the former than in the latter, which inhibits its disciplinary status. Various reasons for this uneven development in the two fields are explored. The paper argues that a paradigm shift must occur for public supply management, which will re-orient it around the concept of the public interest. This will require public supply professionals to participate strategically in public policy-making in order to ascertain and promote the public interest. A policy framework is used to illustrate this re-orientation and to suggest directions for further research.     

Undesirable competition

We show that the entry of private profit-maximising firms makes the consumers worse off compared to having a nationalised monopoly. Such entry increases the nationalised firm’s profit, industry profit, and social welfare, at the expense of the consumers. Our result is important for competition policy.     

DO PARENTAL INVOLVEMENT LAWS REDUCE ADOLESCENT ABORTION RATES?

This study assesses the impact of parental involvement laws on adolescent abortion rates and pregnancy rates. The analysis estimates abortion rate and pregnancy rate models using state-level data pooled over time for adolescents aged 15–17 compared to older teens aged 18–19 and adults aged 20–44. The results indicate that parental involvement laws reduce adolescent abortion rates and may, to a lessor degree, reduce adolescent pregnancy rates. Thus, the findings imply that enforcement of parental involvement laws will increase adolescent fertility rates.     

A new method for measuring congestion in data envelopment analysis

In data envelopment analysis (DEA), there are two principal methods for identifying and measuring congestion: Those of Färe et al. [Färe R, Grosskopf S. When can slacks be used to identify congestion. An answer to W. W. Cooper, L. Seiford, J. Zhu. Socio-Economic Planning Sciences 2001;35:1–10] and Cooper et al. [Cooper WW, Deng H, Huang ZM, Li SX. A one-model approach to congestion in data envelopment analysis. Socio-Economic Planning Sciences 2002;36:231–8]. In the present paper, we focus on the latter work in proposing a new method that requires considerably less computation. Then, by proving a selected theorem, we show that our proposed methodology is indeed equivalent to that of Cooper et al.     

Motivation in the teaching of Physical Education according to the Achievement Goal Theory: methodological considerations

The present study shows how the evaluation of sport motivation according to Achievement Goal Theory is different if the criteria used are predominant goal orientation or motivational profile combination, as well as presenting its relationship with other variables such as the amount of sport practise or the level of competition and success achieved. Seventy two men and women participated, all students of Physical Educational and Sport Science, completing the Questionnaire on Motivational Orientation in Sport ((Guivernau and Duda, Revista de Psicología del Deporte, 5, 1994) a Spanish adaptation of the Task and Ego Orientation in Sport Questionnaire, TEOSQ, (Duda, J Sport Exerc Psychol, 11, 1989)). The results showed the existence of different motivational relationships with variables of the practise of sport, depending on the type of profile used. Finally, the practical implications of these findings are discussed with respect to the motivational climate generated in the teaching of Physical Education.