Model averaging for treatment effect estimation in subgroups

In many clinical trials, biological, pharmacological, or clinical information is used to define candidate subgroups of patients that might have a differential treatment effect. Once the trial results are available, interest will focus on subgroups with an increased treatment effect. Estimating a treatment effect for these groups, together with an adequate uncertainty statement is challenging, owing to the resulting “random high” / selection bias. In this paper, we will investigate Bayesian model averaging to address this problem. The general motivation for the use of model averaging is to realize that subgroup selection can be viewed as model selection, so that methods to deal with model selection uncertainty, such as model averaging, can be used also in this setting. Simulations are used to evaluate the performance of the proposed approach. We illustrate it on an example early‐phase clinical trial.     

CEO burnout,managerial discretion,and firm performance: The role of CEO locus of control,structural power,and organizational factors

Despite the possibility of burnout resulting from dynamics in firms' upper echelons, little if any work has focused on chief executive officer's (CEO's) burnout and firm performance. Drawing on managerial discretion theory, this article analyzes the influence of CEO burnout on firm performance and the moderating roles of the individual (CEO locus of control), structural power (CEO duality and CEO tenure), and organizational characteristics (size, age, and resource availability) related to managerial discretion. Using a sample of 156 CEOs in Swedish firms, we find a negative association between CEOs who report higher burnout and firm performance. Our results confirm that CEO duality and resource availability ameliorate and firm size exacerbates the negative association between CEO burnout and firm performance. Contrary to our expectations, CEO locus of control, CEO tenure, and firm age do not influence this relationship. We discuss the implications of our research for upper echelons theory and strategic leadership theory.     

Stagnation only on the surface? The implications of skill and family responsibilities for the gender wage gap in Sweden, 1974–2010

The wage differential between women and men persists in advanced economies despite the inflow of women into qualified occupations in recent years. Using five waves of the Swedish Level‐of‐Living Survey (LNU), this paper explores the gender wage gap in Sweden during the 1974–2010 period overall and by skill level. The empirical analyses showed that the general gender wage gap has been nearly unchanged for the past 30 years. However, the gender difference in wage in less qualified occupations fell considerably, whereas the gender pay gap remained stable for men and women in qualified occupations. The larger significance of family responsibilities for wages in qualified occupations is one likely explanation for this result.     

The Courtship Dance: Patterns of Nonverbal Synchronization in Opposite-Sex Encounters

This study examines the existence of behavioral correlates of synchronization on different levels of analysis and methods. We were unable to demonstrate a relation between synchronization defined in terms of movement echo or position mirroring and subjective experience of pleasure and interest in opposite-sex encounters. Significant results were found for a phenomenon we describe as hierarchically patterned synchronization. These patterns were identified with the help of a newly developed search algorithm. If a female is interested in a male, highly complex patterns of behavior with a constant time structure emerge. The patterns are pair-specific and independent from behavioral content. This rhythmic structure of interactions is discussed in functional terms of human courtship.     

Bird diversity in a subtropical South-American City: effects of noise levels,arborisation and human population density

Cities are highly modified environments in which the only areas that resemble natural landscapes are urban parks with low human population density. Attempts are frequently made to maintain high bird diversity in cities for aesthetic or educational reasons. However, it remains unclear whether local site characteristics are important in determining bird assemblage composition or whether simplification of the assemblage is an inevitable consequence of the changes associated with human population density. From May 1998 to December 1999, we undertook bird counts at 521 points in Porto Alegre, Rio Grande do Sul, southern Brazil. Our main goal was to understand the pattern of distribution of the bird species richness and density within the city and determine which variables most affect species assemblages. We recorded 132 species belonging to 43 families that are common in Rio Grande do Sul and obtained quantitative data on 121 species in survey sites. The two most abundant species (House Sparrow, Passer domesticus and Rock dove, Columba livia) were exotics. Analysis based on a reduced subset of 134 points surveyed in spring/early summer suggested that there was a North–south gradient in assemblage structure. Variation in assemblage structure was also affected by the number of trees, urban noise and human population density. However, human population density had a much smaller effect on richness and assemblage structure than variables subject to management, such as tree density and noise levels. These results suggest that complex communities may be maintained in densely populated urban areas of sub-tropical South-America given adequate urban planning.     

Democrats and republicans in anthropology and sociology: How do they differ on public policy issues?

The American Sociologist - Within the fields of anthropology and sociology, how do Democrats and Republicans compare in their opinions on issues of economic regulation, personal choice, and the...     

Directory of Literary Magazines

Abstract

Libraries face a crossroads when contemplating serials preservation issues. This paper will discuss the ideas presented during “Serials Preservation: at a Crossroads,” a one-day meeting held in March 2005, and sponsored by the North American Serials Interest Group. Binding, off-site storage, preserving e-journals, and vendor efforts, as well as looking at new developments, such as Google Book Search, offer strategies and challenges for preserving serials and expanding avenues of access for users. Many options exist for serials preservation, but libraries must ultimately consider their individual needs and environment to determine the best serials preservation strategy.     

New Venture Survival: A Review and Extension

This paper provides an evaluative overview of the new venture survival literature. Since Stinchcombe's primary attempt to explain the mortality rates of new ventures, different research fields, including entrepreneurship, management and sociology, have devoted considerable attention to the antecedents of new venture survival. Despite this lively research commitment, a comprehensive review of the literature on new venture survival – as one of the most essential performance measures for new ventures – is missing. Covering 54 years of research, this paper provides an overview of the factors affecting new venture survival and highlights important methodological aspects in this research field. The review concludes by discussing opportunities for future research.