A count data model for gamma waiting times

A new distribution for non-negative integers, or counts, is developed. It is based on the assumption that the waiting times separating consecutive events are independently and identically gamma distributed. Thus, the structural process generating the counts may exhibit duration dependence. In this framework, the frequently observed phenomenon of overdispersion, that is a variance that exceeds the mean, is caused by a decreasing hazard function of the gamma distributed waiting times, while an increasing hazard leads to underdispersion at the level of the counts. A Monte Carlo simulation and an application to fertility data illustrate the performance of the new distribution.     

Randbemerkungen zum Ambiente des Kongresses

Ohne Zusammenfassung     

Historical regional patterns of infant mortality in Austria

First an overview is given of the secular decline of infant mortality in Austria between 1820 and 1950 is given. Second the study analyses the historical regional differences of infant mortality in Austria comparing data for all 99 political districts (Politische Bezirke) for the period 1900 to 1950. The most important results are: At the turn of the 19th century infant mortality rates were generally lower in Alpine than in non-alpine regions and lower in cities than in their surrounding areas. This geographical pattern which remained constant until the 1950s was solely determined by differences in post-neonatal mortality rates. Plausible explanations for these regional differences are discussed.En premier lieu cette étude fournit une vue d'ensemble du déclin séculaire de la mortalité infantile en Autriche en 1820 et 1950. Elle analyse ensuite les différences régionales de mortalité infantile en comparant les données des 99 districts politiques (Politische Bezirke) autrichiens, de 1900 à 1950. Les principaux résultats sont les suivants: à la fin du XIX^e siècle les taux de mortalité infantile étaient en général plus faibles dans les régions alpines que dans les autres et plus faibles dans les villes que dans les aires adjacentes. Ce modèle géographique, qui est resté le même jusqu'en 1950, était uniquement déterminé par les différences entre les taux de mortalité post-néonatale. Des explications plausibles de ces différences régionales sont discutées ici.     

12‐Month‐Old Infants' Perception of Attention Direction in Static Video Images

Twelve‐month‐old infants' ability to perceive gaze direction in static video images was investigated. The images showed a woman who performed attention‐directing actions by looking or pointing toward 1 of 4 objects positioned in front of her (2 on each side). When the model just pointed at the objects, she looked straight ahead, and when she just looked, her hands were hidden below the tabletop. An eye movement system (TOBII) was used to register the gaze of the participants. We found that the infants clearly discriminated the gaze directions to the objects. There was no tendency to mix up the 2 object positions, located 10° apart, on the same side of the model. The infants spent more time looking at the attended objects than the unattended ones and they shifted gaze more often from the face of the model to the attended object than to the unattended objects. Pointing did not significantly increase the infants' tendency to move gaze to the attended object, irrespective of whether the pointing gesture was accompanied by looking or not. In all conditions the infants spent most of the time looking at the model's face. This tendency was especially noticeable in the pointing‐only condition and the condition where the model just looked straight ahead.     

Das Geheimnis des Alltäglichen

Since the 80ies Michel de Certeau’s analyses of everyday life had influenced the development of Cultural Studies. For example the practices of consumption and reception were described as resistant tactics in the work of John Fiske. But many aspects of de Certeau’s complex theory were not considered. Against this background his works is surveyed in the context of theories of everyday life. The study shows that the potential of de Certeau’s critical cultural analysis has yet to be disclosed and realized. So he has developed a subtle theory of everyday practices, delineated a science of the singular and explored the relationships between the unconscious and everyday life/between utopia and everyday life.     

Managing Potential Health Risks from Electric Powerlines: A Decision Analysis Caught in Controversy

Over the past 20 years, several epidemiological studies have found an association between exposure to electromagnetic fields (EMFs) and health effects, including childhood leukemia and adult brain cancer. However, experts strongly disagree about whether this association is causal and, if so, how strong it is. In this article, we examine several alternatives to reduce EMFs from sources of the California power grid, including undergrounding distribution and transmission lines and reconfiguring or rephasing lines. The alternatives were evaluated in terms of the potential health risk reduction, cost, impacts on service reliability, property values, and many other consequences. Because of the uncertainty about an EMF-health link, the main effort was to determine the sensitivity of the decisions to the probability and seriousness of an EMF hazard. User-friendly computer models were developed to allow stakeholders to change the model assumptions and parameters to analyze the impacts of their own assumptions and estimates on the decision. The analysis clearly demonstrated that only four of the many concerns raised by the stakeholders could make a difference in the decision: health risks, costs, service reliability, and property values. Whether undergrounding, moderate alternatives for EMF reduction, or no change was the best decision depended on a few key factors, including the probability that EMF exposure is a hazard, the severity of this hazard, how the EMF reduction measures are financed, and the impacts on property values. While the analysis did not resolve the EMF issues, it showed that even in the most controversial settings, a little analysis goes a long way to clarifying the issues and to focus the debate.     

Understanding Social Change in Conducting Research on Adolescence

In the present essay, we focus on G. Stanley Hall's contributions to the study of the role of social change for adolescent development. After introducing Hall's main ideas, we discuss recent demands adolescents face because of social change and how Hall's work could inform research on adolescent development in times of social change.