Positive Effekte sozialen Faulenzens beim Lösen komplexer Probleme

The term “social loafing” refers to a decrease in motivation and achievement in group work due to sinking responsibility of the individual for the groups’ outcome. Recent studies assume a paradoxical relation between motivation and outcome, which should produce better outcome with decreased motivation. The current study addresses this question. Two experiments with N=60 subjects working in groups of 3 are reported. Subjects had to deal with a computer simulated scenario of a fire fighting situation. There was a simple and a more complex version; also, individual responsibility for the groups’ outcome was either given (coactive condition) or not (collective condition). During experiment 1, subjects could only deal with their own section of the scenario; in experiment 2, they were allowed to work on the whole field. Dependent variables were effort (in terms of commands given) and achievement (in terms of space saved). It turned out that under collective responsibility effort was reduced but this did not lead to decreased achievement. Under the complex condition, with decreased effort even an increase in achievement could be demonstrated. Implications for the collective effort model presented by Karau and Williams are discussed.     

A bias analysis of Weibull models under heaped data

Retrospectively collected duration data are often reported incorrectly. An important type of such an error is heaping—respondents tend to round-off or round-up the data according to some rule of thumb. For two special cases of the Weibull model we study the behaviour of the ‘naive estimators’, which simply ignore the measurement error due to heaping, and derive closed expressions for the asymptotic bias. These results give a formal justification of empirical evidence and simulation-based findings reported in the literature. Additionally, situations where a remarkable bias has to be expected can be identified, and an exact bias correction can be performed.     

Buchbesprechungen / Book reviews

Literatur / Books

Buchbesprechungen / Book reviews     

Projection Measures And Estimation Variances Of Intensities

The paper investigates random processes of geometrical objects in Euclidean spaces. General properties of the measure of total projections are derived by means of Palm distribution. Explicit formulas for variances of the projection measure are obtained for Poisson point processes of compact sets.

Intensity estimators of fibre (surface) processes are then studied by means of projection measures. Classification of direct and indirect probes is introduced. The indirect sampling design of vertical sections and projections is generalized and its statistical properties derived.     

Job satisfaction and mental health of temporary agency workers in Europe: a systematic review and research agenda

ABSTRACT

The current systematic literature review aimed to analyse the associations between temporary agency work (TAW), job satisfaction, and mental health in Europe, as well as to outline a future research agenda. Twenty-eight scientific articles were identified by searching different data bases (i.e. PSYNDEX, PsycINFO, PubMed, and Web of Science) for the time span from January 2000 to December 2016. Our review reveals first that TAW is not consistently negatively related to job satisfaction. However, job insecurity and working conditions are important mediators in the relation of TAW and lowered job satisfaction. Second, TAW is not consistently related to all investigated types of mental health impairments. However, when focusing on specific outcomes and comparing temporary agency workers to permanent employees, we still find consistent evidence regarding higher levels of depression and fatigue among temporary agency workers. Inconsistent associations between TAW, job satisfaction and mental health can partly be attributed to unfavourable methodological aspects of the included primary studies. To address these aspects, future research should consider applying a standard measurement of TAW, including a minimum of meaningful confounding variables, improving the operationalisation of outcome variables and the study design.     

Weighted Approximations to Continuous Time Martingales with Applications

A weighted approximation to a sequence of continuous time martingales by a time transformed Wiener process is established. The basic tool of proof is the Skorohod imbedding for martingale difference sequences. As an application of the main result a useful weighted approximation to the randomly weighted uniform empirical process is derived. A number of other applications are also discussed.     

Remote control: measuring performance for value creation and governance of globally distributed knowledge work

This article examines the governance of globally distributed knowledge work. To measure performance in knowledge work, it is important to focus on what the knowledge workers do and hence view knowledge as something one does, namely the practices, instead of something one has. By following the practices of knowledge work, it was possible to evaluate the effect of measures related to organizational processes, and identify what was not well covered by the measurement tool. Strategic and long term needs such as learning and employee competence are better managed through projects. This article shows how work performance in international organizations needs two different measures: one tool for measuring short-term value creation linked to the organizational processes; and, one tool for measuring long-term value creation linked to the practices of service work made in projects. Global governance of distributed employees is therefore successfully managed through key performance measures and through understanding projects through their multiple contributions, at both an individual and an organizational level. Global long term governance needs are strategic for the entire firm. The paper rests on an in-depth empirical case study of an international professional service firm.     

Unions and innovative activity in Germany

This study is the first attempt to investigate the influence of unions on innovative activities in Germany at the industry level. Econometric models estimated by a highly robust method and submitted to a number of specification tests indicate that trade unions do not have a negative impact on innovative activity which is measured by either the percentage of revenues spent on R&D or the percentage of employees working in R&D. This finding is consistent with evidence on the influence of unions on productivity in Germany and with considerations about the German system of industrial relations.     

Randomization of neighbour balanced generalized Youden designs

If a crossover design with more than two treatments is carryover balanced, then the usual randomization of experimental units and periods would destroy the neighbour structure of the design. As an alternative, Bailey [1985. Restricted randomization for neighbour-balanced designs. Statist. Decisions Suppl. 2, 237–248] considered randomization of experimental units and of treatment labels, which leaves the neighbour structure intact. She has shown that, if there are no carryover effects, this randomization validates the row–column model, provided the starting design is a generalized Latin square. We extend this result to generalized Youden designs where either the number of experimental units is a multiple of the number of treatments or the number of periods is equal to the number of treatments. For the situation when there are carryover effects we show for so-called totally balanced designs that the variance of the estimates of treatment differences does not change in the presence of carryover effects, while the estimated variance of this estimate becomes conservative.