Experts in experiments

An ever increasing number of experiments attempts to elicit risk preferences of a population of interest with the aim of calibrating parameters used in economic models. We are concerned with two types of selection effects, which may affect the external validity of standard experiments: Sampling from a narrowly defined population of students (??experimenter-induced selection??) and self-selection due to non-response or incomplete response of participants in a random sample from a broad population. We find that both types of selection lead to a sample of experts: Participants perform significantly better than the general population, in the sense of fewer violations of revealed preference conditions. Self-selection within a broad population does not seem to matter for average preferences. In contrast, sampling from a student population leads to lower estimates of average risk aversion and loss aversion parameters. Furthermore, it dramatically reduces the amount of heterogeneity in all parameters.     

Spectral estimation for locally stationary time series with missing observations

Time series arising in practice often have an inherently irregular sampling structure or missing values, that can arise for example due to a faulty measuring device or complex time-dependent nature. Spectral decomposition of time series is a traditionally useful tool for data variability analysis. However, existing methods for spectral estimation often assume a regularly-sampled time series, or require modifications to cope with irregular or ‘gappy’ data. Additionally, many techniques also assume that the time series are stationary, which in the majority of cases is demonstrably not appropriate. This article addresses the topic of spectral estimation of a non-stationary time series sampled with missing data. The time series is modelled as a locally stationary wavelet process in the sense introduced by Nason et al. (J. R. Stat. Soc. B 62(2):271–292, 2000) and its realization is assumed to feature missing observations. Our work proposes an estimator (the periodogram) for the process wavelet spectrum, which copes with the missing data whilst relaxing the strong assumption of stationarity. At the centre of our construction are second generation wavelets built by means of the lifting scheme (Sweldens, Wavelet Applications in Signal and Image Processing III, Proc. SPIE, vol. 2569, pp. 68–79, 1995), designed to cope with irregular data. We investigate the theoretical properties of our proposed periodogram, and show that it can be smoothed to produce a bias-corrected spectral estimate by adopting a penalized least squares criterion. We demonstrate our method with real data and simulated examples.     

Schulleitungscoaching – Konzeption und Ausbildungsevaluation

Since principals in schools are increasingly turning into managers of educational institutions, coaching approaches have an increasing importance. Accordingly, the Bavarian Ministry for Education and Culture in cooperation with the National Institute for Quality in Schools and Educational Research and the Academy of Teacher Education and Personnel Management has introduced the project ?Coaching – an Instrument to Professionalise School-based Leadership“. The project involves exemplary coachings of school management teams and the training of coaches with a focus on school-related issues at the University of Innsbruck. The training of coaches is based on a special curriculum, which was evaluated using a multi-methods approach. The outcomes show that the coaching model is accepted by coaches and that the training is of high quality     

Real-life closeness of social media contacts and depressive symptoms among university students

ABSTRACT

Objective: To examine the association between degree of real-life closeness of social media (SM) contacts and depressive symptoms. Participants: Students ages 18–30 (N = 1124) were recruited in August 2016. Methods: Participants completed an online survey assessing SM use and depression. We used multivariable logistic regression to assess associations between real-life closeness of SM contacts and depressive symptoms. Results: After controlling for covariates, each 10% increase in the proportion of SM friends with whom participants had no face-to-face relationship was associated with a 9% increase in odds of depressive symptoms (AOR = 1.09; 95% CI = 1.05–1.13). However, each 10% increase in the proportion of SM friends with whom participants had a close face-to-face relationship was associated with a 7% decrease in depressive symptoms (AOR = 0.93; 95% CI = 0.89–0.97). Conclusions: Having no in-person relationship with SM contacts is associated with increased depressive symptoms; however, having close in-person relationships with SM contacts is associated with decreased depressive symptoms.     

Marital Violence: An Integrated Systems Approach

A review of current issues and approaches to the problem of marital violence is presented. In order to understand volatile relationships, these attachments are discussed within the context of the normal progression of events in the formation and development of a marriage. A systems model that integrates current conceptual thinking is presented, The article concludes with a paradigm for therapeutic decision-making and strategies that flow from the integrated systems model.     

Immigration and the Wages of Native Workers: Spatial versus Occupational Approaches

Using data from the Current Population Survey, we study the impact of the increasing proportion of immigrants on the wages of native workers. Two different approaches are contrasted. The most common method has been the spatial approach that uses some geographic unit of analysis to investigate the multivariate association between the proportion of immigrants and the wages of native workers. Previous studies using the spatial approach have generally found little evidence of a significant negative effect. We propose, however, a contrasting method that represents an occupational approach in which occupations are the unit of analysis to investigate the impact of the proportion immigrant. This occupational approach avoids the bias that is inherent in the spatial approach due to the endogenous nature of immigrants' decisions about where to reside and the economic opportunities of local areas. In contrast to the spatial approach, our results using the same data but employing the occupational approach yield consistently negative net effects of the proportion immigrant on the wages of native workers during the period from 1994 to 2006.     

The Importance of Social Cues for Discretionary Health Services Utilization: The Case of Infertility

Infertility is a discretionary health condition; although it carries with it important life course implications, treatment is rarely necessary for health reasons. Sociological theories of medical help‐seeking emphasize demographic factors, perceived need, and enabling conditions in health services utilization, but we find that social cues are also strongly associated with health services utilization for infertility. Adjusted for conventional predictors of medical help‐seeking, several social cue indicators have significant associations with utilization, including having friends and family with children, perceiving infertility stigma, and having a partner and/or family member who encourages treatment. Perceived need accounts for the largest portion of the variation in utilization. Enabling conditions explain less of the variance than social cues. Social cues should be especially important for discretionary health services utilization. Studies of service utilization for discretionary health conditions should explicitly incorporate a range of measures of social cues into their models.     

Inter- and transdisciplinary approaches to population–environment research for sustainability aims: a review and appraisal

The causes and consequences of demographic changes for the environment, and the possible ways of influencing population dynamics to achieve ‘sustainability’, have been the subject of many debates in science and policy in recent decades. However, the body of knowledge concerning relationships between population dynamics and sustainability is quite fragmented, dispersed over many disciplines, and encompasses diverse theories, paradigms and methodologies. This paper reviews four selected frameworks: linear, multiplicative, mediated, and system-theoretical approaches and perspectives. We represent how population–environment relationships are conceptualized, provide examples of research questions and accepted approaches, and critically assess their utility for different sorts of research for sustainable development. We note the growing recognition of the value of embracing complexity in population–environment research, and how this is consistent with normative aims of development.     

Editorial Note

The issue of acculturation is an important one in the history and historiography of Dutch colonialism in the Indies. In so far as there is any substantial orthodoxy, it is that the orientalisation of Java's Dutch communities had become very marked by the late seventeenth century and remained so for the next two hundred years. It was only with the changed global circumstances of the late colonial era, c. 1880 onwards, that Western modes began to assert themselves effectively against those of the East. In turn, the profound acculturation prior to that date of the Dutch colonial communities in the Indies, and in Java in particular, came to be associated with the notion of a Tempo Doeloe [lit: 'time past'], which provided a salient contrast to the markers of a subsequent, late-colonial 'modernity' This paper questions some of the basic assumptions of this orthodoxy, from a postcolonial standpoint that challenges its inherent colonial-era binaries. The nineteenth century family histories of a number of men and women - Suikerlords [Sugar Lords] and their Ladies - from the elite strata of Dutch colonial society in the Indies demonstrates that the cultural and social nexus between The Netherlands and the Indies throughout the nineteenth century was a good deal more intimate, and colonial identity significantly more ambivalent, than enduring stereotypes might allow.