Figuren der reflektierten Improvisation in der sozialp?dagogischen Jugendberatung

Zusammenfassung In dem Aufsatz wird untersucht, was ungeplante und unplanbare Ereignisse für den Bereich der sozialp?dagogischen Jugendberatung bedeuten. Zun?chst wird erl?utert, inwiefern sozialp?dagogisches Beratungshandeln stets Elemente der Improvisation in sich birgt. Es folgen Analysen zur Frage, wie das blo?e Improvisieren zum reflektierten Improvisieren qualifiziert werden kann. Abschlie?end wird dargelegt, welche Handlungsfiguren durch die reflektierte Improvisation in der sozialp?dagogischen Beratung entstehen.

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The author analyses the meaning of not planed and impossible to plan events in the field of social pedagogical counselling of young people. As a first step he describes how far the social pedagogical counselling always includes elements of improvisation. An analysis of the question how norma improvisation could be qualified as reflective improvisation follows. Finally the authors shows which forms of acting emerge using the reflected improvisation in the social pedagogical counselling.

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Stefan Danner, Dr. phil., Professor für Erziehungswissenschaft an der Hochschule für Technik, Wirtschaft und Kultur Leipzig.

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Arbeitsschwerpunkte: Bildungstheorie, Didaktik der Elementarp?dagogik, Jugendarbeit und Erwachsenenbildung, Methoden der Evaluationsforschung.     

Smooth backfitting in practice

Summary.  Compared with the classical backfitting of Buja, Hastie and Tibshirani, the smooth backfitting estimator (SBE) of Mammen, Linton and Nielsen not only provides complete asymptotic theory under weaker conditions but is also more efficient, robust and easier to calculate. However, the original paper describing the SBE method is complex and the practical as well as the theoretical advantages of the method have still neither been recognized nor accepted by the statistical community. We focus on a clear presentation of the idea, the main theoretical results and practical aspects like implementation and simplification of the algorithm. We introduce a feasible cross-validation procedure and apply it to the problem of data-driven bandwidth choice for the SBE. By simulations it is shown that the SBE and our cross-validation work very well indeed. In particular, the SBE is less affected by sparseness of data in high dimensional regression problems or strongly correlated designs. The SBE has reasonable performance even in 100-dimensional additive regression problems.     

Modeling asset returns with alternative stable distributions

In the 1960's Benoit Mandelbrot and Eugene Fama argued strongly in favor of the stable Paretian distribution as a model for the unconditional distribution of asset returns. Although a substantial body of subsequent empirical studies supported this position, the stable Paretian model plays a minor role in current empirical work.

While in the economics and finance literature stable distributions are virtually exclusively associated with stable Paretian distributions, in this paper we adopt a more fundamental view and extend the concept of stability to a variety of probabilistic schemes. These schemes give rise to alternative stable distributions, which we compare empirically using S&P 500 stock return data. In this comparison the Weibull distribution, associated with both the nonrandom-minimum and geometric-random summation schemes dominates the other stable distributions considered-including the stable Paretian model.     

Non-monotonicity in the longevity�Cincome relationship

In this essay, I empirically analyze the relationship between income and life expectancy for pensioners in the public pension system in Germany and find that the relationship is non-monotonic for major sub-groups in the data. Due to the application of non-parametric methods, this cannot be explained as an artifact of the estimation technique or by anomalies of the data, and the finding is robust against the inclusion of control variables. Furthermore, I theoretically derive a non-monotonic relationship between income and longevity, based on heterogeneous elasticities of labor supply and otherwise standard assumptions.     

The use and effectiveness of top executive dismissal

We provide a systematic assessment of the empirical evidence on the use and effectiveness of top executive dismissal as a governance and performance improvement mechanism. Our results suggest that poor individual and firm performance significantly increase the likelihood of executive dismissal. A strong power base might help under-performing top executives to extend their tenure in office, but effective ownership and governance structures can provide a counterweight to such entrenchment behaviors. However, our review casts doubt on the effectiveness of top executive dismissal as a means to enhance future firm performance: employing meta-analytical techniques we show that, although the dismissal announcement leads to positive abnormal returns, it has no significant effect on long-term measures of firm performance. On the basis of our findings, we develop a conceptual model of the possible antecedents and consequences of top executive dismissal. We derive implications for boards involved in situations of executive dismissal and for the successors of dismissed executives, and we provide directions for future leadership research on executive dismissal.     

Pricing of flexible products

The pricing of flexible products is a new price discrimination practice that can enable firms to increase revenues under capacity considerations. A flexible product is defined as a good or service with at least one product attribute not fully specified at the time of the purchase, leaving the seller with at least two alternatives for the final product design and the ability to assign consumers to one of these alternatives at a later date. Flexible products enable sellers to better utilized capacity, as well as, to segment consumers and price discriminate according to different levels of flexibility. We empirically analyze consumer purchase behavior for flexible products based on a large field study of a low-cost airline. At this low-cost airline, consumers can select the level of flexibility of the flexible product. We identify the drivers of purchase behavior by analyzing the impact of consumers?? flexibility and search behavior and the price discount of the flexible ticket. Further, we estimate the revenue and profit effects of flexible products.