On generalized degrees of freedom with application in linear mixed models selection

The concept of degrees of freedom plays an important role in statistical modeling and is commonly used for measuring model complexity. The number of unknown parameters, which is typically used as the degrees of freedom in linear regression models, may fail to work in some modeling procedures, in particular for linear mixed effects models. In this article, we propose a new definition of generalized degrees of freedom in linear mixed effects models. It is derived from using the sum of the sensitivity of the expected fitted values with respect to their underlying true means. We explore and compare data perturbation and the residual bootstrap to empirically estimate model complexity. We also show that this empirical generalized degrees of freedom measure satisfies some desirable properties and is useful for the selection of linear mixed effects models.     

Die Analyse sozialer Kontexte

Individual behaviour is always embedded in social contexts such as networks, companies, neighbourhoods. They constitute a central condition to explain individual behaviour. We discuss major problems of context analysis. We first define context to then explore how contexts affect behaviour—the social mechanisms. We specify a multilevel model to demonstrate theoretical problems linking levels and the associated problems of adequate statistical modelling. An example is the explanation of individual behaviour by country level data.We then discuss cross pressures between contexts; here, we show how similar theoretical approaches of Simmel and Lazarsfeld are. Finally, we turn to two other problems of context analyses: non-linear effects and selection bias. We resume our arguments by suggesting a preliminary theory of contexts and strategies for future research.     

Prosocial behaviour,inclusion and exclusion: why and when do we behave prosocially? / Comportamiento prosocial,inclusión y exclusión: ¿cuándo y por qué adoptamos comportamientos prosociales?

Two experiments analysed the influence of inclusion versus exclusion on prosocial behaviour. In Study 1, evidence for the social reconnection hypothesis was found. In Study 2, a cross-over interactive effect is demonstrated: excluded individuals tended to be more prosocial when their competence was affected than when their popularity was affected. However, included people were more prosocial than excluded people when their popularity was affected, but they were less prosocial when their competence was highlighted. Besides, Study 2 has shown that affiliation motivation mediates the effect of exclusion on prosocial behaviour, and thus: (1) excluded individuals endorse lower levels of affiliation motivation with their rejecters than included individuals do with individuals who have included them; and (2) individuals with higher levels of affiliation motivation engage in higher prosocial behaviour levels when the behaviour is oriented to people with whom the chance to reconnect exists, but not when it is oriented to people with whom there is no possibility for future affiliation.     

How Common is Men's Self-Reported Sexual Interest in Prepubescent Children?

Consistent evidence exists for sexual interest in children in nonclinical/nonforensic male populations. However, prevalences for community men's self-reported sexual interest in children have been based on indiscriminate definitions including postpubescent individuals, age-restricted samples, and/or small convenience samples. The present research assessed men's self-reported sexual interest in children (including child prostitution and child sex tourism) on the community level and examined the link between strictly defined sexual fantasies and behaviors involving prepubescent children. In an online survey of 8,718 German men, 4.1% reported sexual fantasies involving prepubescent children, 3.2% reported sexual offending against prepubescent children, and 0.1% reported a pedophilic sexual preference. Sexual fantasies involving prepubescent children were positively related to sexual offending against prepubescent children. Sexual interest in children was associated with subjectively perceived need for therapeutic help. In contrast to findings from forensic samples, men who reported child pornography use exclusively were identified as a subgroup differing from contact sexual offenders against prepubescent children and men who reported both child pornography use and contact sexual offenses against prepubescent children. The empirical link between child-related sexual fantasies and sexual victimization of prepubescent children and high levels of subjective distress from this inclination underscore the importance of evidence-based child sexual abuse prevention approaches in the community. Findings are discussed in terms of their relation to pedophilic disorder.     

Management-Derailment und System-Derailment

The discussion about Management Derailment (MD) has been intensifying in the past few years. We want to contribute to this discussion by considering MD in connection with System Derailment, a topic that is often the subject of debates on economic and business ethics. The current debate is characterized by the notion that in order to increase profits, companies employ more and more ethically questionable and sometimes illegal practices. In particular, we propose that socially irresponsible corporate governance corresponds with morally derailed members of the (a) top management, and (b) with mid and lower management. Specifically, we ask if moral derailment by top managers (“bad management”) can also lead to economic derailment (“mad management”), while ongoing work pressures for mid and lower managers can also be linked to their moral and individual derailment (“sad management”).     

Organisationsentwicklung in M&A Prozessen

Technical issues like legal matters or different types of due diligence predominate during the execution of mergers and acquisitions. Personnel issues only get considered during the post-merger integration phase. However, the success of mergers and acquisitions depends considerably on the early and correct involvement of the human resource and organization development (OD) department in every phase of the merger.     

South African quality of life: A research note

A nation-wide survey (n=5587) was conducted in 1982/83 with a view to developing a reliable cross-cultural index of quality of life for South Africa. Findings confirmed the known under-privileged position of blacks relative to other groups in terms of some 60 objective and subjective indicators. Contrary to expectations the results of factor and regression analyses indicated that the linear additive model of quality of life-as-a-whole cannot account for its full complexity. The possibility is considered that more broadly symbolic factors related to relative deprivation may make an independent contribution to perceived overall well-being. In conclusion, a single cross-cultural albeit multi-item measure of South African quality of life is recommended.     

On subjective probability and related problems

Of late, probability subjectivism was resuscitated by the development of statistical decision theory. In the decision model, which is briefly described in the paper, the knowledge of a probability distribution over the states of nature plays a decisive role. What sources of probability knowledge are legitimate, or at all possible, is the main point at issue. Different definitions, evaluations, and foundations of probability are narrated, discussed, and weighed against each other. The typical research strategy of the statistician is set against axiomatics of subjective or mathematical probability. Finally, the epistemological roots of the probability concept are located by the author in what he calls the etiality principle.