Estimation of the mean of the exponential distribution with an outlying observation

Given a life testing experiment consisting of n items, n-1 of which have the expected life λ while one could have an expected life λ/α with 0 < α < 1 the problem is. to find a mean square error (MSE) minimizing estimation function. The standard estimators for the homogeneous case (α = 1) overestimate the expected life and their MSE tend to infinity when a tends to 0.

Looking at the estimation problem as an insurance (see Anscombe (1960)) two different “testimators” are compared with respect to their MSE, Numerical results show that an estimation function based on the “Epstein-statistic” x_(n)/[xbar] is the best one.     

Körper-Kunst in der Kinderklinik – ein interdisziplinäres Projekt zwischen Pädiatrie, Tanztheater und Psychosomatik

On the basis of the deconstructive idea of dance as a means to experience inner coherences as well as dehiscences within the body, an interdisciplinary project between psychosomatic medicine, pediatrics and dance is outlined. Social processes between dancers, adolescents and trainer within a single clinically more in detail described workshop are presented and related to the situation of chronically ill children. Hereby, a reintegration of the rejected and negatively charged body in chronic conditions is initialized.     

The drivers of work engagement: A meta-analytic review of longitudinal evidence

ABSTRACT

Work engagement is currently one of the most popular outcomes in occupational health psychology. According to the motivational process within the job demands-resources (JD-R) framework, job resources stimulate work engagement, which in turn fosters job performance. While the general positive impact of job resources on work engagement is well established, it remains unclear how different types of job resources differentially predict work engagement over time. In our meta-analytic review, we identified 55 longitudinal studies that investigate the impact of various job resources on work engagement. To uncover the drivers of work engagement, we examined the differential impact of job resources on work engagement at group level, leader level, and organisational level via meta-analytic structural equation modelling. The findings suggest that job resources at each of the three levels predict work engagement over time. However, organisational-level resources (reflecting how the work is organised, designed and managed) contribute much more strongly to work engagement than group-level, and leader-level resources. All three levels of job resources and work engagement are highly stable. We advocate for interventions at any of the three levels. However, interventions at the organisational-level are most promising for enhancing work engagement and we thus strongly recommend strengthening those job resources.     

The evolutionary stability of optimism,pessimism, and complete ignorance

Theory and Decision - We seek an evolutionary explanation for why in some situations humans maintain either optimistic or pessimistic attitudes toward uncertainty and are ignorant to relevant...     

Secondary School Transition and the Use of Different Sources of Information for the Construction of the Academic Self‐concept

This study focuses on processes involved in students' academic self‐concept constructions before, during, and after secondary school transition. The study is based on a four‐wave longitudinal dataset (N = 1953). Structural equation modeling showed that during school transition, the impact of grades on students' academic self‐concepts in Math and English decreased whereas the effects of maternal competence perceptions increased. After the transition, the effects of grades increased, while the effects maternal competence beliefs decreased again. The results are interpreted in terms of differential emphasizing of sources of information for students' self‐concept construction. During school transition, elementary school grades lost informational value for self‐evaluations due to the changed frame of reference. To secure stable and valid self‐assessments, students emphasized other sources than grades; in this, case information obtained through parental competence appraisals. After transition, when valid grades were available for the students' constructions again, the temporarily heightened parental influence decreased again.     

Estimation of interregional migration streams from place-of-birth-by-residence data

Place-of-birth-by-residence data, tabulated by age and sex for the same areal units in two successive censuses, have been used to estimate intercensal net migration flows. However, a fuller use of the same data permits the estimation of place-to-place flows. This paper describes a method for estimating intercensal migration streams from place-of-birth-by-residence data and illustrates its application with data on the white female native population of the United States.     

Framing political public relations: Measuring success of political communication strategies in Germany

The main goal of political public relations is the use of media outlets to communicate specific political interpretations of issues in the hope of garnering public support for political policies. This study elaborates on the question how successful political PR is at bringing its specific perspectives into the media. It uses the ‘framing’ concept to analyse the meanings and contexts of media coverage and political PR during the national debate on immigration in Germany between May 2000 and March 2002. The results show a high level of correlation between the preferred thematic and position frames of the political players and those in the press coverage. Yet, the media examined clearly did not have a passive relationship to PR. The findings indicate that journalists tend to use their power to alter PR messages when the communications from political players do not have a distinct focus and/or when the PR focuses were not among the (mainstream) aspects dominating the general political debate.     

Does exposure to unawareness affect risk preferences? A preliminary result

One fundamental assumption often made in the literature on unawareness is that risk preferences are invariant to changes of awareness. We study how exposure to unawareness affects choices under risk. Participants in our experiment choose repeatedly between varying sure outcomes and a lottery in three phases. All treatments are exactly identical in phase 1 and phase 3, but differ in phase 2. There are five different treatments pertaining to the lottery faced in phase 2: The control treatment (i.e., a standard lottery), the treatment with awareness of unawareness of lottery outcomes but known number of outcomes, the treatment with awareness of unawareness of outcomes but with unknown number of outcomes, the treatment with unawareness of unawareness of some outcomes, and the treatment with an ambiguous lottery. We study both whether behavior differs in phase 3 across treatments (between subjects effect) and whether differences of subjects’ behavior between phases 1 and phase 3 differ across treatments (within subject effects). We observe no significant treatment effects.     

The job demands-resources model: A meta-analytic review of longitudinal studies

The job demands-resources (JD-R) model is an influential framework to understand how job characteristics foster employee well-being. Differing from the cross-sectional focus of most JD-R model reviews, this meta-analytic review uses longitudinal evidence to validate the essential assumptions within the JD-R model. We highlight two aspects: (1) The assessment of the methodological quality of the available longitudinal studies, and (2) the examination of the essential assumptions – the impact of job characteristics on well-being, and vice-versa – with meta-analytic structural equation modelling (metaSEM). We included 74 studies and evaluated their quality. Eighteen studies suffered from serious methodological shortcomings, whereas 29 studies (39%) were considered high-quality studies. Our meta-analytic structural equation models confirmed the essential assumptions simultaneously. The quality of the studies also had an influence on the goodness-of-fit indices. The models with reciprocal assumptions between job characteristics and well-being fitted the data best. The findings of this meta-analytic review suggest that the JD-R model is an excellent theoretical basis to assess employee well-being for a broad range of organisations. However, more research is needed to clarify the reciprocal relationships between job characteristics and employee well-being, as well as the different influences of challenging and hindering job demands on work engagement.