Housing and children: simultaneous decisions?—a cohort study of young adults’ housing and family formation decision

This study contributes to earlier research on homeownership and childbearing by taking into account the potential simultaneity between these two life events. A dataset comprising three different Swedish birth cohorts suggests that these are events that are indeed simultaneous. Different tests indicate that taking this simultaneity into account gives an overall statistically significant improvement of the model fit. However, this result is most obvious for those young adults who faced increasing problems on the housing market. The childbearing decision of these cohorts also seems to be more sensitive to changes in the user cost.     

On global integer extrema of real-valued box-constrained multivariate quadratic functions

Determining global integer extrema of an real-valued box-constrained multivariate quadratic functions is a very difficult task. In this paper, we present an analytic method, which is based on a combinatorial optimization approach in order to calculate global integer extrema of a real-valued box-constrained multivariate quadratic function, whereby this problem will be proven to be as NP-hard via solving it by a Travelling Salesman instance. Instead, we solve it using eigenvalue theory, which allows us to calculate the eigenvalues of an arbitrary symmetric matrix using Newton’s method, which converges quadratically and in addition yields a Jordan normal form with \(1 \times 1\)-blocks, from which a special representation of the multivariate quadratic function based on affine linear functions can be derived. Finally, global integer minimizers can be calculated dynamically and efficiently most often in a small amount of time using the Fourier–Motzkin- and a Branch and Bound like Dijkstra-algorithm. As an application, we consider a box-constrained bivariate and multivariate quadratic function with ten arguments.     

Design recommendations for the creation of icons for the elderly

During employment of icons in order to represent system functions, specific user requirements from elderly people have not been scientifically gathered and thus will merely be considered during the process of system design. The survey, with explicit consideration of technology acceptance and experience of 120 elderly probands, looked into the comprehension of four different classes of non-animated graphical representations. It was shown that among elderly, the use of photos compared to pictograms or clip art leads to a significantly higher recognition rate. The mapping of actions rather than objects leads to a further reduction of the error probability and is thus, especially in the context of telemedicine, preferable for the target group.     

The effect of fast and slow decisions on risk taking

We experimentally compare fast and slow decisions in a series of experiments on financial risk taking in three countries involving over 1700 subjects. To manipulate fast and slow decisions, subjects were randomly allocated to responding within 7 seconds (time pressure) or waiting for at least 7 or 20 seconds (time delay) before responding. To control for different effects of time pressure and time delay on measurement noise, we estimate separate parameters for noise and risk preferences within a random utility framework. We find that time pressure increases risk aversion for gains and risk taking for losses compared to time delay, implying that time pressure increases the reflection effect of Prospect Theory. The results for gains are weaker and less robust than the results for losses. We find no significant difference between time pressure and time delay for loss aversion (tested in only one of the experiments). Time delay also leads to less measurement noise than time pressure and unconstrained decisions, and appears to be an effective way of decreasing noise in experiments.     

Organisationskultur im Spielfilm

By analyzing cinema films, specific organizational cultures can be illustrated. The culture of prison as a “total institution” is explained on the basis of the movie “The Shawshank Redemption” (1994). With regard to the developing friendship between the former banker Andy Dufresne who is innocently convicted and the homicide delinquent Ellis Boyd Redding typical characteristics of a total institution are pointed out. Furthermore, the psychological function those characteristics serve for employees, inmates and even for the society as a whole is analyzed. Central to this interpretation is thinking of the prison as a father substitute. Many interactions become comprehensible viewed in this context. Additionally, the prison represents a huge object of projection which facilitates the collective release of aggression.     

Presence and process of fear of birth during pregnancy—Findings from a longitudinal cohort study

Background

The prevalence of fear of birth has been estimated between 8–30%, but there is considerable heterogeneity in research design, definitions, measurement tools used and populations. There are some inconclusive findings about the stability of childbirth fear.

Multiple hypothesis tests based On conditional differences in means

Many hypothesis tests are univariate tests and cannot cope with multiple hypothesis without an auxiliary procedure as e. g. the Bonferroni-Holm-procedure. At the same time, there is an urgent need for testing multiple hypothesis due to the very simple existing methods as the Bonferroni-correction or the Bonferroni-Holm-procedure, which suffers from a very small local significance level to detect statistical inferences or the drawback that logical and statistical dependencies among the test statistics are not used, whereby its detection is NP-hard. In honour of this occasion, we present a multiple hypothesis test for i.i.d. random variables based on conditional differences in means, which is capable to cope with multiple hypothesis and does not suffer on such drawbacks as the Bonferroni-correction or the Bonferroni-Holm-procedure. Thereby, the computation time can be neglected.