Test for model selection using Cramér–von Mises distance in a fixed design regression setting

In this paper a test for model selection is proposed which extends the usual goodness-of-fit test in several ways. It is assumed that the underlying distribution H depends on a covariate value in a fixed design setting. Secondly, instead of one parametric class we consider two competing classes one of which may contain the underlying distribution. The test allows to select one of two equally treated model classes which fits the underlying distribution better. To define the distance of distributions various measures are available. Here the Cramér-von Mises has been chosen. The null hypothesis that both parametric classes have the same distance to the underlying distribution H can be checked by means of a test statistic, the asymptotic properties of which are shown under a set of suitable conditions. The performance of the test is demonstrated by Monte Carlo simulations. Finally, the procedure is applied to a data set from an endurance test on electric motors.     

HOW MARKET FRAGMENTATION CAN FACILITATE COLLUSION

Economists have recommended the fragmentation of capacities before regulated markets are liberalized because static oligopoly models imply that outcomes approximate perfect competition with a fragmented enough market structure. This intuition fails under collusion. When individual firms are capacity constrained relative to total demand, the fragmentation of capacity facilitates collusion and increases the highest sustainable collusive price. Collusive outcomes remain feasible even for arbitrarily fragmented capacity. These results can explain the finding in Sweeting (2007 , Economic Journal, 117, 654–685), that dramatic fragmentation of generation capacity in the English electricity industry did not reduce price cost margins.     

Inequality in mobilizing online help after a negative life event: the role of education,digital skills,and capital-enhancing Internet use

Many studies have investigated inequalities in coping with stressful life events and often education is found to play a role in this (the higher educated are usually more successful in dealing with their problems in terms of well-being consequences). We examine whether something similar occurs on the Internet, whether the higher educated are more successful in mobilizing help online, and whether this is related to their digital skills and the way in which they use the Internet. With the latter, we link online coping to digital inequality research. Researchers have investigated digital inequalities with regard to skills and types of Internet use. However, we know little about the extent to which these factors translate into inequalities in resources mobilized from the Internet. This latter type of inequality is highly relevant, since it is an intermediary step between Internet use and (improved) well-being and life chances. Using a large sample of individuals living in the Netherlands, we find educational differences in the mobilization of online problem-focused coping resources, but no differences with regard to online socioemotional or disengagement coping resources. The educational inequalities in online coping are somewhat smaller than educational inequalities in offline coping, leading to remarkable consequences for social policy. Furthermore, we find a relatively complex pattern of interrelations between offline inequality (education) and different types of digital inequality (skills, usage, resources). In our conclusions we make a plea for more research on outcomes of Internet use and we discuss the implications of our findings for further research.     

Empfehlungen der Deutschen Gesellschaft für Soziologie (DGS) zur Ausgestaltung soziologischer Bachelor- und Master-Studiengänge

Ohne Zusammenfassung     

<Emphasis Type="Italic">Frank Kalter:</Emphasis> Chancen,Fouls und Abseitsfallen. Migranten im deutschen Ligenfußball

Ohne Zusammenfassung

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INDIVIDUAL RISK ATTITUDES: MEASUREMENT,DETERMINANTS, AND BEHAVIORAL CONSEQUENCES

This paper studies risk attitudes using a large representative survey and a complementary experiment conducted with a representative subject pool in subjects' homes. Using a question asking people about their willingness to take risks “in general”, we find that gender, age, height, and parental background have an economically significant impact on willingness to take risks. The experiment confirms the behavioral validity of this measure, using paid lottery choices. Turning to other questions about risk attitudes in specific contexts, we find similar results on the determinants of risk attitudes, and also shed light on the deeper question of stability of risk attitudes across contexts. We conduct a horse race of the ability of different measures to explain risky behaviors such as holdings stocks, occupational choice, and smoking. The question about risk taking in general generates the best all‐round predictor of risky behavior.     

Nonsense regressions due to neglected time-varying means

Regressions of two independent time series are considered. The variables are covariance stationary but display time-varying although not trending means. Two prominent examples are level shifts due to structural breaks and seasonally varying means. If the variation of the means is not taken into account, this induces nonsense correlation. The asymptotic treatment is supplemented by experimental evidence. This work was carried out while visiting Universidad Carlos III de Madrid. Financial support from the European Commission through the Training and Mobility of Researchers programme is gratefully acknowledged. An earlier version was circulated as Universidad Carlos III working paper 99-78. I am grateful to Artur da Silva Lopes for comments that improved the presentation.