Group Buying of Competing Retailers

Under group buying, quantity discounts are offered based on the buyers' aggregated purchasing quantity, instead of individual quantities. As the price decreases with the total quantity, buyers receive lower prices than they otherwise would be able to obtain individually. Previous studies on group buying focus on the benefit buyers receive in reduced acquisition costs or enhanced bargaining power. In this paper, we show that buyers can instead get hurt from such cooperation. Specifically, we consider a two‐level distribution channel with a single manufacturer and two retailers who compete for end customers. We show that, under linear demand curves, group buying is always preferable for symmetric (i.e., identical) retailers. For asymmetric retailers (i.e., differing in market base and/or efficiency), group buying is beneficial to the smaller (or less efficient) player. However, it can be detrimental to the larger (or more efficient) one. Despite the lower wholesale price under group buying, the manufacturer can receive a higher revenue. Interestingly, group buying is more likely to form when retailers are competitive in different dimensions. These insights are shown to be robust under general nonlinear demand curves, except for constant elastic demand with low demand elasticity.     

A note about calibrated prediction regions and distributions

In this work we address the problem of the construction of prediction regions and distribution functions, with particular regard to the multidimensional setting. Firstly, we define a simple procedure for calculating the predictive distribution function which gives improved prediction limits. Secondly, with a multivariate generalization of a result presented in Ueki and Fueda (2007), we propose a method for correcting estimative prediction regions, to reduce their coverage error to the third-order accuracy. The improved prediction regions and the associated distribution functions are easy to calculate using a suitable bootstrap procedure. Examples of application are included, showing the good performance of the proposed method, even if we consider an approximated model for prediction purposes.     

Markov Chain Monte Carlo model selection for DAG models

We present a methodology for Bayesian model choice and averaging in Gaussian directed acyclic graphs (dags). The dimension-changing move involves adding or dropping a (directed) edge from the graph. The methodology employs the results in Geiger and Heckerman and searches directly in the space of all dags. Model determination is carried out by implementing a reversible jump Markov Chain Monte Carlo sampler. To achieve this aim we rely on the concept of adjacency matrices, which provides a relatively inexpensive check for acyclicity. The performance of our procedure is illustrated by means of two simulated datasets, as well as one real dataset.     

Does Religious Diversity in Health Team Composition Affect Efficiency? Evidence from Dubai

Team cultural diversity, the degree to which working team members differ in culture‐related factors, may affect healthcare teams’ outcomes. This paper focuses on one particular source of cultural diversity, namely religion, and examines its relation to the production efficiency of hospital wards. Building on the categorization‐elaboration model of organizational diversity, the authors test an empirical model positing that team religious diversity has non‐linear effects on efficiency, and considering the role of moderating variables of the relation diversity–efficiency. Empirically, the authors adopt a two‐step approach, whereby the first step applies data envelopment analysis to estimate efficiency scores for each team, and the second investigates the effect of diversity and of moderating variables. The model is tested on a sample of hospital wards from three large hospitals in Dubai. The results suggest an inverse U‐shaped relation between religious diversity and the wards’ efficiency. Evidence is provided that the relation is moderated by task complexity, task conflict, team leader tenure and diversity in nationality. This study advances research on the management of hospital team diversity by emphasizing the complexity of diversity effects and the importance of contextual factors.     

Suicide risk and exposure to mobbing

The aim of this study was to study suicide risk in subjects exposed to mobbing, that is, systematic psychological harassment in the workplace. Such psychological harassment, unique to the workplace, threatens both the emotional well-being and professional ability of its victims. The items of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) that assess suicide risk were studied in 102 individuals who were exposed to mobbing. The results indicated that individuals exposed to mobbing had clear differences on the MMPI-2 from normative samples. In addition, those who appeared to be at risk for suicide differed in their scores from those not at risk. Implications for psychopathology and suicide preventions are discussed.     

The Public–Private Job Satisfaction Differential in Italy

Abstract. This paper uses Italian survey data for 1995 to study the differences in satisfaction for six non‐pecuniary job attributes between public and private sector workers. Results indicate that public employees differ from private employees in the way they evaluate satisfaction with job security, consideration by colleagues, and safety and health job features, whereas there are no differences in their assessment of satisfaction with effort levels and interest for the job. In particular, we find that the premium for public employees is quantitatively higher, especially in the case of satisfaction with employment losses. Moreover, there are significant differences in the determinants of satisfaction across sectors.     

Relative labour deprivation and urban migration in Turkey

The paper develops a concept, a measure and an index of relative labour deprivation and applies these tools to measure deprivation in urban areas of South-East Turkey. It is shown how a Yitzhaki-type of relative deprivation index can be applied to the labor domain and be extended to take into account the notion of reference group derived from modern theories of social justice. In the absence of panel or longitudinal data, such measure results particularly useful to derive policy recommendations for areas characterized by heterogeneous communities. Contrary to what conventional statistics and wisdom would suggest, we find migrants from Eastern Turkey to be less relatively labour deprived than other groups of migrants.     

An SEIR Model with Time-Varying Coefficients for Analyzing the SARS-CoV-2 Epidemic

In this study, we propose a time-dependent susceptible-exposed-infected-recovered (SEIR) model for the analysis of the SARS-CoV-2 epidemic outbreak in three different countries, the United States, Italy, and Iceland using public data inherent the numbers of the epidemic wave. Since several types and grades of actions were adopted by the governments, including travel restrictions, social distancing, or limitation of movement, we want to investigate how these measures can affect the epidemic curve of the infectious population. The parameters of interest for the SEIR model were estimated employing a composite likelihood approach. Moreover, standard errors have been corrected for temporal dependence. The adoption of restrictive measures results in flatten epidemic curves, and the future evolution indicated a decrease in the number of cases.     

Occupational stress and biomechanical risk in a high fashion clothing company

Psychosocial discomfort may amplify job-related risk factors. The aim of this study is to evaluate job stress in a high fashion clothing company with upper limb biomechanical overload due to repetitive and forceful manual activities. Biomechanical risk was analyzed and in part reduced using the OCRA Check list. A total of 518 workers (433 females and 85 males) were investigated to determine anxiety (by STAI 1 and 2), occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms. Final biomechanical assessment did not reveal high risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due, probably, to very low decision latitude. It was suggested that job strain may increase the perception of symptoms. Moreover, the result of this study indicates that musculoskeletal overload has to be further analyzed since its low level is not in agreement with the level of discomfort due to the repetitive tasks.     

Surviving in Psychiatry as a Systemic Therapist

Although family therapy was born to deal with problems posed by severe mental disorders, systemic therapists today tend to drift away from the field of psychiatry The author refers to his own experience in psychiatry to argue in favour of the presence of the systemic model within the field: systemic understanding might be precious to counterbalance the tendency toward too easy a reliance on bio‐psychiatry and pharmacology. In turn, keeping close to psychiatry and to its problems can be useful to systemic therapists, by involving them in social and epistemological queries that are otherwise extraneous to professionals mainly devoted to private practice.