Evaluation of procedures for improving population estimates for small areas

"We provide and illustrate methods for evaluating across-the-board ratio estimation and synthetic estimation, two techniques that might be used for improving population estimates for small areas. The methods emphasize determination of a break-even accuracy of knowledge concerning externally obtained population totals, which marks the point at which improvement occurs." The techniques are illustrated using 1980 U.S. census data.     

Bildungschancen von Grundschülern: Die Bedeutung des Klassen- und Schulkontextes am Übergang auf die Sekundarstufe I

Do context characteristics of class and school have an impact on elementary school pupils’ educational opportunities in addition to the confirmed individual effects of social origin and academic performance? The paper investigates the influence of the contextual performance- and SES-level as well as of the ethnic composition of the context on the probability of (1) obtaining a recommendation for higher secondary schools (Gymnasium) and (2) effectively attending a higher secondary school. To this end, we base our theoretical framework on the distinction between primary and secondary effects, as introduced by Boudon (1974), and extend it by a contextual perspective, as well as the related decisions of parents and teachers. The analyses are based on a survey of all 4^th graders of elementary schools in the city of Wiesbaden (Germany) during the school year 2006/07. The context effects are modelled by using logistic multilevel models. The results show that the affiliation to both school- and class context explains about 10 per cent of the total variance of academic achievement. Additionally, there is evidence that the context effects significantly influence the individual educational opportunities in particular when the individual marks are controlled for (secondary context effects). Furthermore, especially the SES-related context composition influences the educational outcomes when controlling for relevant individual variables. With respect to the accomplished transitions to the Gymnasium, the performance level of the school also has significant impact. Contrary to previous studies, we could not detect any effect of the ethnic composition of the context when SES is controlled for. While there are effects of the class context as well as of the school context with the educational recommendation as dependent variable, only the school context is of relevance concerning the effectively attained school transition.     

Multiple Regression Model Averaging and the Focused Information Criterion With an Application to Portfolio Choice

ABSTRACT

We consider multiple regression (MR) model averaging using the focused information criterion (FIC). Our approach is motivated by the problem of implementing a mean-variance portfolio choice rule. The usual approach is to estimate parameters ignoring the intention to use them in portfolio choice. We develop an estimation method that focuses on the trading rule of interest. Asymptotic distributions of submodel estimators in the MR case are derived using a localization framework. The localization is of both regression coefficients and error covariances. Distributions of submodel estimators are used for model selection with the FIC. This allows comparison of submodels using the risk of portfolio rule estimators. FIC model averaging estimators are then characterized. This extension further improves risk properties. We show in simulations that applying these methods in the portfolio choice case results in improved estimates compared with several competitors. An application to futures data shows superior performance as well.     

Habitat rehabilitation in urban waterways: the ecological potential of bank protection structures for benthic invertebrates

Compensating for the adverse ecological impacts of waterway development and improving their ecological functioning to achieve good ecological potential (GEP) have become mandatory within the European Union (EU). The technical rehabilitation measures presented here aim to functionally minimize the hydraulic impacts of navigation on aquatic biota in highly urbanized waterways. Their ecological functioning and potential to enhance biodiversity locally was assessed by comparing their macro-invertebrate community composition with nearby non-restored sites. Rehabilitation led to lower hydraulic impact on the littoral zone, which in turn led to the presence of otherwise missing macrophytes and the occurrence of organic mud habitats colonized by invertebrates typically rare in urban waterways. While the control sites were dominated by few, mostly invasive taxa in vast numbers, the rehabilitated sites exhibited a highly diverse community with 22 protected mollusc and insect taxa typically found in the oxbow communities of natural rivers. This major improvement was however not detected using the core metrics of the legally required national assessment tools of the EU Water Framework Directive. Overall results proved the success of this type of rehabilitation measure with respect to improving biodiversity, but they also showed the limiting and key factors influencing the macro-invertebrate communities of highly deteriorated urban waterways. Indeed, future implementations of this type of rehabilitation measure should consider spatial extent, water exchange rates, temporal succession of vegetation and adaptive management to improve its ecological functioning.     

The job demands-resources model: A meta-analytic review of longitudinal studies

The job demands-resources (JD-R) model is an influential framework to understand how job characteristics foster employee well-being. Differing from the cross-sectional focus of most JD-R model reviews, this meta-analytic review uses longitudinal evidence to validate the essential assumptions within the JD-R model. We highlight two aspects: (1) The assessment of the methodological quality of the available longitudinal studies, and (2) the examination of the essential assumptions – the impact of job characteristics on well-being, and vice-versa – with meta-analytic structural equation modelling (metaSEM). We included 74 studies and evaluated their quality. Eighteen studies suffered from serious methodological shortcomings, whereas 29 studies (39%) were considered high-quality studies. Our meta-analytic structural equation models confirmed the essential assumptions simultaneously. The quality of the studies also had an influence on the goodness-of-fit indices. The models with reciprocal assumptions between job characteristics and well-being fitted the data best. The findings of this meta-analytic review suggest that the JD-R model is an excellent theoretical basis to assess employee well-being for a broad range of organisations. However, more research is needed to clarify the reciprocal relationships between job characteristics and employee well-being, as well as the different influences of challenging and hindering job demands on work engagement.     

Attitude theory and behavioral costs

The Fishbein and Ajzen reasoned action model is briefly introduced and some theoretical aspects of the model arc discussed. Based on a critical analysis of the act and behavioral category concepts in their model an alternative concept, ‘behavioral field’, is introduced. A behavioral field is defined as: ‘the total of acts that are perceived by the acting individual as leading to a common goal or valued state’. Then a distinction is made between goal acts and instrumental acts, Goal acts lead to goal attainment. Instrumental acts will bring the individual into the direction of his goal. It is argued that for acts that are predominantly instrumental other substitutable acts are available. The choice between suhstitutable instrumental acts is governed by both expected outcomes and the behavioral costs attached to the acts. Behavioral costs are defined as the behavioral price relative to the behavioral budget. The behavioral price is determined by tile time, psychic and physical task demand. The behavioral budget is a function of the goal importance of the behavioral field. Some further aspects of behavioral costs are then discussed. Several arguments to treat costs and outcomes separately in the explanation of behavior, are elaborated. Then some implications from the behavioral cost concept are drawn for attitude theory. Finally the entangling of costs and value is briefly discussed.