Bayesian Methods for Improving Credit Scoring Models

We propose a Bayesian methodology that enables banks to improve their credit scoring models by imposing prior information. As prior information, we use coefficients from credit scoring models estimated on other data sets. Through simulations, we explore the default prediction power of three Bayesian estimators in three different scenarios and find that they perform better than standard maximum likelihood estimates. We recommend that banks consider Bayesian estimation for internal and regulatory default prediction models.Credit Scoring, Bayesian Inference, Bankruptcy Prediction

How do Rating Agencies Score in Predicting Firm Performance

We use dynamic panel analysis to examine whether credit rating agencies achieve what they claim to achieve, namely, look into the future when assigning their ratings. We find that Moody's ratings help predict individual financial ratios over a horizon of up to five years. Ratings also predict a multivariate credit score, again over five years. The contribution of ratings appears to be economically significant and robust for different specifications.Credit Ratings, Predictive ability, Dynamic Panel Model.

The use of data at school: concepts, strategies, experiences

Vergleichsarbeiten sowie Lernstandserhebungen haben bisher kaum zur Steigerung der Unterrichtsqualität beigetragen. Während die Struktur des Angebots an Leistungsdaten bereits ein relativ hohes Niveau erreicht hat, liegen die Ursachen vor allem in der komplexen Struktur der Nutzung von Leistungsdaten. Mögliche Ursachen für die geringen Auswirkungen der Leistungserhebungen auf die Verbesserung der Unterrichtsqualität werden im Beitrag auf strukturelle und individuelle Voraussetzungen für Innovationen zurückgeführt. (DIPF/Orig.).Comparative achievement tests have scarcely contributed to improve the quality of instruction so far. While the structure of the provided performance data has reached a relatively high level, the reasons lie mainly in the complex patterns of using these data. This paper ascribes some possible reasons for the poor effects of achievement tests on the improvement of instruction to structural and individual requirements for innovations. (DIPF/Orig.)

Asymmetry and performance metrics for equity returns

An assumption of symmetric asset returns, together with globally risk averse utility functions, is unappealing for fund managers and other activist investors, whose preferences switch between risk aversion on the downside and risk seeking on the upside. A performance return criterion is originated that is more consistent with the implicit Friedman-Savage utility ordering. Adapted from recent developments in the income distribution literature, the proposed metric weights the lower versus upper conditional expected returns, while a dual spread or dispersion metric also exists. The resulting performance metric is easy to compute. A point of departure is the conventional Sharpe performance ratio, with the empirical comparisons extending to a range of existing performance criteria. In contrast, the proposed W-metric results in different and more embracing performance rankings

Predatory short sales and bailouts

This paper extends the literature on predatory short selling and bailouts through a joint analysis of the two. We consider a model with informed short sales, as well as uninformed predatory short sales, which can trigger the inefficient liquidation of a firm. We obtain several novel results: A government commitment to bail out insolvent firms with positive probability can increase welfare because it selectively deters predatory short selling without hampering desirable informed short sales. Contrasting a common view, bailouts can be optimal ex ante but undesirable ex post. Furthermore, bailouts in our model are a better policy tool than short selling restrictions. Welfare gains from the bailout policy are unevenly distributed: shareholders gain while taxpayers lose. Bailout taxes allow ex-ante Pareto improvements

Fitting of dust spectra with genetic algorithms - I. Perspectives & Limitations

Aims: We present an automatised fitting procedure for the IR range of AGB star spectra. Furthermore we explore the possibilities and boundaries of this method. Methods: We combine the radiative transfer code DUSTY with the genetic algorithm PIKAIA in order to improve an existing spectral fit significantly. Results: In order to test the routine we carried out a performance test by feeding an artificially generated input spectrum into the program. Indeed the routine performed as expected, so, as a more realistic test set-up, we tried to create model fits for ISO spectra of selected AGB stars. Here we were not only able to improve existing fits, but also to show that a slightly altered dust composition may give a better fit for some objects. Conclusion: The use of a genetic algorithm in order to automatise the process of fitting stellar spectra seems to be very promising. We were able to improve existing fits and further offer a quantitative method to compare different models with each other. Nevertheless this method still needs to be studied and tested in more detail.Comment: 9 pages, 5 figures, accepted for publication in Astronomy and Astrophysic

Mandatory sustainability reporting in Germany: does size matter?

This article studies how German firms evaluate a recent national corporate social responsibility (CSR) law based on a European Union directive and the burden they expect regarding their organizational responsibilities due to mandatory sustainability reporting. One hundred and fifty-one firms of different sizes directly or indirectly affected by the law are included in the survey and their responses empirically analyzed using two-tailed t-tests and simple linear regression. Anchoring the discussion in stakeholder theory and the small and medium-sized enterprise (SME) literature while considering large-firm idiosyncrasies, the results show differing effects on SMEs and large firms as well as firms which are directly and indirectly affected. Findings show that firm size only matters for the evaluation of the law by directly affected firms, while size does not matter in the case of indirectly affected firms. Possible moderators of this evaluation are grounded in the resource-based theory and formalization of CSR. This article contributes to the understanding of when firm size matters in the case of mandatory sustainability reporting and underlines the role of organizational resources and capabilities as well as the special position of SMEs

The arrangement of syllabi as one of the reasons for the erosion of affective objectives at school

Für die Erosion affektiver Ziele in der Schule kommt eine Reihe von Gründen in Frage. Die Autoren gehen von der Annahme aus, daß einer dieser Gründe in der Gestaltung von Lehrplänen liegt. Mit einer inhaltsanalytischen Untersuchung der Lehrpläne für die allgemeinbildenden höheren Schulen in Österreich konnte diese These erhärtet werden. Die Erosion affektiver Ziele erfolgt auf verschiedenen Wegen. In den Lehrplänen mancher Fächer wird überhaupt auf sie verzichtet, in anderen eine inhaltliche Bestimmung versäumt oder das taxonomische Niveau drastisch reduziert. Verbreitet sind auch die Aussparung affektiver Ziele aus Verfahrensaussagen, die sich unmittelbar auf die Gestaltung des Unterrichts beziehen, und Formulierungen, die die Auffassung nahelegen, daß Wissen Einstellungen und Werthaltungen von selbst bewirkt. Die Erosion affektiver Ziele ist nicht zuletzt deshalb so bemerkenswert, weil affektive Ziele dort, wo es gilt, schulisches Lernen bzw. einzelne Unterrichtsgegenstände zu rechtfertigen, einen hohen Stellenwert besitzen. (DIPF/Orig.)The authors of the following article argue that one of the reasons for the erosion of affective objectives at school lies in the arrangement of the syllabus. This tesis was substantiated by a content analysis of the syllabi for secondary schools in Austria. The erosion takes place in different ways. Syllabi of some subjects do without it, in others a definition with regard to the contents is neglected in the affective domain or the taxonomic levels are reduced drastically. It is common or at least widespread to exclude affective objectives from statements in the syllabus, which refer directly to training. And many definitions can be found, which suggest that knowledge effects attitudes and affective behavior automatically. Last but not least the erosion of affective objectives is so remarkable because they are of great importance for the justification of school learning respective single subjects

A Numerical Investigation of the Oil Pump Suction Behaviour in a Hermetic Reciprocating Compressor

In addition to the adequate lubrication of the moving parts, the oil flow in a hermetic reciprocating compressor has a significant influence on the thermal characteristics of a compressor. The present work is concerned with the investigation of the oil pump system of a reciprocating hermetic compressor used in household refrigeration appliances. The considered oil pump system consists of a centrifugal pump immersed in the oil sump of the hermetic compressor and a helical groove machined on the crankshaft. The focus of this work lies on the immersed part of the centrifugal oil pump and its interaction with the oil in the oil sump. To analyse the flow in the immersed area of the oil pump, the commercial computational fluid dynamics (CFD) software ANSYS Fluent is used. The free surface of the oil flow is modelled with the volume of fluid (VOF) method. A numerical investigation is used to study the influence of the immersion depth and the oil pump design on oil mass flow rate and flow field at the oil pump intake. To evaluate the oil pump regarding the applicability in variable speed compressors, the influence of the rotational speed on the oil mass flow is also explored