Estimation of geodesic tortuosity and constrictivity in stationary random closed sets

We investigate the problem of estimating geodesic tortuosity and constrictivity as two structural characteristics of stationary random closed sets. They are of central importance for the analysis of effective transport properties in porous or composite materials. Loosely speaking, geodesic tortuosity measures the windedness of paths, whereas the notion of constrictivity captures the appearance of bottlenecks resulting from narrow passages within a given materials phase. We first provide mathematically precise definitions of these quantities and introduce appropriate estimators. Then, we show strong consistency of these estimators for unboundedly growing sampling windows. In order to apply our estimators to real data sets, the extent of edge effects needs to be controlled. This is illustrated using a model for a multiphase material that is incorporated in solid oxide fuel cells.     

L'effet des obstacles aux échanges sur l'emploi généré par les chaînes d'approvisionnement mondiales

Les auteurs étudient l'effet des obstacles aux échanges internationaux de biens et de services sur les marchés du travail des pays producteurs en partant des estimations du BIT sur l'emploi imputable aux chaînes d'approvisionnement mondiales. L'analyse empirique confirme largement les prédictions d'un modèle théorique calibré avec des données de la base WIOD (2000 et 2011). Les obstacles au commerce de produits manufacturés ou de services ont un effet transfrontalier, intrasectoriel et intersectoriel, sur l'emploi, qui reflète l'interdépendance croissante entre pays et secteurs. L'effet intersectoriel s'affirme avec le temps. Les politiques commerciales semblent donc pouvoir avoir des effets externes importants sur les marchés du travail étrangers.     

The Legacy of the Great Recession in Italy: A Wider Geographical,Gender, and Generational Gap in Working Life Expectancy

Under the pressure of population aging the Italian pension system has undergone reforms to increase labor force participation and retirement age, and, thus, the length of working life. However, how the duration of working life has developed in recent years is not well understood. This paper is the first to analyze trends in working life expectancy in Italy. We use data from a nationally representative longitudinal sample of 880,000 individuals from 2003 to 2013 and estimate working life expectancy by gender, occupational category, and region of residence using a Markov chain approach. We document large and increasing heterogeneity in the length of working life. From 2003–2004 to 2012–2013, working life expectancy for men declined from 35.2 to 27.2 years and for women from 34.7 to 23.7 years, increasing the gender gap to 3.5 years. Both young and old were hit, as roughly half of the decline was attributable to ages below 40, half above 40. Working life expectancy declined for all occupational groups, but those in manual occupations lost most, 8.5 years (men) and 10.5 years (women). The North–South economic gradient widened such that men living in the North were expected to work 8 years longer than women living in the South. The fraction of working life of total life expectancy at age 15 declined to record lows at 40% for men and 34% for women in 2012–2013. Policies aiming at increasing total population working life expectancy need to take into consideration the socio-demographic disparities highlighted by our results.

     

Evaluating school and parent reports of the national student achievement testing system (SIMCE) in Chile: Access,comprehension, and use

This evaluation examined school and parent reports of the national student achievement testing system (SIMCE) in Chile regarding three dimensions: access, comprehension, and use. We conducted phone surveys with a representative sample of directors (N = 375), teachers (N = 1145) and parents (N = 625), and we collected more in-depth data through interviews and focus groups in 16 of these schools. The results indicate that access to the reports is not an obstacle to use for school actors, but it is for parents. While summative ratings of the reports in terms of their clarity and utility were generally very positive, the actual recall and interpretation of even basic information (assessed through case scenarios) was incorrect for a majority of teachers and parents, and reported uses of the information were both intended and unintended in nature. We also found some statistically significant differences regarding comprehension and use among subgroups of our sample. Our findings are especially relevant given the expectations attached to the use of the reports for school improvement on the one hand, and parents’ behavior as critical consumers of education on the other hand.     

Self-Directed Gambling Changes: Trajectory of Problem Gambling Severity in Absence of Treatment

Most problem gamblers do not seek formal treatment, recovering on their own through cognitive re-appraisal or self-help strategies. Although barriers to treatment have been extensively studied, there is a paucity of research on self-directed changes in problem gambling and very few studies have examined these changes prospectively. The aim of this study was to examine the trajectory of gambling severity and behavior change over an 18-month period, among a sample of non-treatment seeking/attending problem gamblers recruited from the community (N?=?204) interested in quitting or reducing gambling. Separate mixed effects models revealed that in absence of formal treatment, significant reductions in gambling severity, frequency, and amount gambled could be observed over the course of a 6 to 9-month period and that changes experienced within the first 12 months were maintained for an extended 6 months. Problem gambling severity at baseline was significantly associated with changes in severity over time, such that participants with more severe gambling problems demonstrated greater reductions in their gambling severity over time. A total of 11.1% of participants gambled within a low-risk threshold at 18 months, although 28.7% of the sample reported consecutive gambling severity scores below problem levels for the duration of 1 year or longer. The findings suggest that among problem gamblers motivated to quit or reduce their gambling, significant self-directed changes in gambling severity can occur over a relatively short time. Additional prospective studies are needed to document the role of specific self-help tools or thought processes in exacting gambling changes.     

Psychological Vulnerability and Problem Gambling: The Mediational Role of Cognitive Distortions

Despite numerous studies demonstrating the influence of cognitive distortions on gambling problem severity, empirical data regarding the role of psychological vulnerability on the latter is limited. Hence, this study assesses the mediating effect of cognitive distortions between psychological vulnerability (personality and mood), and gambling problem severity. It also verifies whether the relationships between these variables differs according to the preferred gambling activity. The sample is composed of 272 male gamblers [191 poker players; 81 video lottery terminal (VLT) players] aged between 18 and 82 years (M = 35.2). Bootstrap analysis results revealed that cognitive distortions mediate the effect of narcissism on gambling problem severity for both groups. The level of depression for VLT players significantly predicted gambling problem severity, both directly and indirectly via the mediating effect of cognitive distortions. Mediation analyses also indicated that narcissism had an indirect impact on problem gambling through cognitive distortions for both groups. These findings suggest that certain vulnerabilities related to personality and mood may influence cognitive distortion intensity and gambling problem severity. In addition, psychological vulnerabilities could differ based on preferred gambling activity. These results may be useful for prevention policies, identifying high risk gamblers and planning psychological interventions.     

Nah der Wissenschaft und fern der Führung in einer Fach‑/Expertenlaufbahn?

In order to motivate and retain technical employees, representatives of strategic career management face the challenge of establishing alternative career paths in addition to the common leadership/management career. Surveying a sample of 629 doctorate holders from the STEM fields, we differentiated between five career paths within and beyond structured career models. Structured career ladders were predominantly present in major enterprises. Female participants less frequently reported to be part of a structured career path. Entering a leadership/management career seems to occur at a later stage compared to other paths. Generally, advancement on a leadership/management path was related to stronger increases in incentives than climbing up the technical/expert or project management ladders. Contrary to our expectations, we did not find members of a technical/expert career to work closer to basic research and their initial qualification than their colleagues on other career paths. Members of leadership/management paths reported to have significantly more leadership responsibility than those working on alternative paths.     

Trust and Society: Suggestions for Further Development of Niklas Luhmann's Theory of Trust

This paper addresses an apparent gap in the work of Niklas Luhmann. While the issue of trust continues to receive widespread attention in the social sciences, Luhmann's interest in this topic declined following the development of his systems theory. It is argued that this decline does not reflect any diminished relevance of trust for systems theory, but rather that the architectural remodeling of theory cannot easily be applied to the issue of trust. Here, the issue of trust is reconceptualized as a connection medium. This entails a reconstruction of Luhmann's early theory of trust, especially with regard to function and social positioning. In this context, trust can in turn be linked to the concept of medium in Luhmann's late work. As a connection medium, trust mediates between the different levels of sociality—interaction, organization, and society. These theoretical considerations are employed to develop a more applied framework for empirical research, with a brief case study from southern Italy. From this perspective, the idea of trust as society's glue is seen to be overly simplistic. The common ethical understanding that more trust leads to a better society is also questioned on the grounds that social cooperation can also lead to social sclerosis. Finally, risk and trust are shown to accommodate the formation of different cultures of trust. The paper shows how Luhmann's updated version of trust can inspire current research and enhance our understanding of how trust operates in contemporary society.     

Making the Case for Interpretative Phenomenological Analysis with LGBTGEQ+ Persons and Communities

ABSTRACT

The emergence of interpretative phenomenological analysis (IPA) in qualitative scholarship offers a means to derive in-depth meaning attending to the complexities of lived experience. IPA extends qualitative inquiry through a double hermeneutic whereby the researcher is making sense of the experiences of participants who are making sense of a phenomenon. In this article, the authors present seminal empirical studies using IPA with lesbian, gay, bisexual, transgender, gender expansive, queer communities, argue a rationale for its usefulness, discuss methodological insights and strategies, and offer potential future directions.     

PEER PRESSURE: EXPERIMENTAL EVIDENCE FROM RESTROOM BEHAVIOR

We provide experimental evidence on the effect of peer pressure on individual behavior. Specifically, we study the effect of being exposed to an observer in a public restroom on handwashing and urinal flushing behavior. Our estimates show that being exposed to an observer increases the probability of handwashing by 13 percentage points and the probability of urinal flushing by 15 percentage points. Given that handwashing and urinal flushing have social benefits that exceed individual benefits, our findings provide support for peer pressure as an additional way of addressing the social suboptimality arising from externalities. (JEL C91, C93)