Two-moment decision models and rank-dependent utility

This paper extends results on the consistency of two-moment decision models with expected utility to rank-dependent utility preferences. The representations of expected utility and rank-dependent utility by --preferences have very similar comparative statics properties for linear distribution classes, except for the behavior with respect to small independent risks.I thank Soo Hong Chew for helpful discussion and three anonymous referees for valuable comments.     

Sector-specific capital, “Bang-bang” investment,and the Filippov solution

Bang-bang investment in a two-sector growth model with immobile capital is rational and leads to a unique and globally stable long-run equilibrium along a sliding trajectory. This steady state coincides with the stationary equilibrium in the traditional model with non-sector-specific capital.This article was written while the authors were visiting scholars at Cornell University. We gratefully acknowledge financial assistance from the Erasmus University Trust Fund and the Netherlands Scientific Organization. We would like to thank, without implicating, two anonymous referees, Martijn Herrmann, Jean-Marie Viaene, Claus Weddepohl, and the participants of seminars at the University of Maryland, the University of Montreal, and Erasmus University Rotterdam for perceptive remarks and useful comments. Jeroen Hinloopen and Rien Wagenvoort provided able graphical assistance. The views expressed in this article are those of the authors and not necessarily those of the World Bank.     

Traumberuf oder Verlegenheitslösung?

So far relatively little is known about the situation of Ph.D. students in media and communication research. The main purpose of this study is, therefore, to shed light on the employment and working conditions for young scholars on their way to their doctoral degrees. We conducted a survey of 281 Ph.D. students in Germany, Switzerland and Austria. The results show that, on the one hand, young scholars are intrinsically highly motivated to do their jobs. On the other hand, they perceive an academic career as a very uncertain venture with many obstacles. Furthermore, several types of Ph.D. students can be distinguished: idealists, careerists and waverers. It is shown that only the idealists conform to the concept of a productive and interested scholar. The results are discussed in terms of their importance for the future development of the field.     

What Causes the Positive Price-Turnover Correlation in European Housing Markets?

This paper examines what determines the correlation between prices and turnover in European housing markets. Using a panel vector autoregressive model, we find that there is a particularly strong feedback mechanism between prices and turnover. Momentum effects are another important reason why prices and turnover are correlated. Common underlying factors, such as GDP and interest rates, also explain part of the price-turnover correlation. The results in this paper imply that, to understand price and turnover dynamics, it is important to model prices and turnover as two interdependent processes. There is a considerable bias in the coefficient estimates of standard house price models if this dependency is not explicitly taken into account.     

Ein Näherungsverfahren zur Berechnung optimaler Pläne für messende Prüfung bei bekannten Kosten und bekannter Verteilung der Schlechtanteile in den vorgelegten Liefermengen

Ohne Zusammenfassung     

Zur verteilungsfreien Ableitung der Streuung von Regressionskoeffizienten ohne Voraussetzung der Nullhypothese

Ohne Zusammenfassung     

Tests und Konfidenzintervalle für exponentielle Verteilungen und deren Anwendung auf einige diskrete Verteilungen

Zusammenfassung Es werden Verteilungen betrachtet, die (bezüglich irgendeines Ma?es) eine Dichte der GestaltC(ϑ) exp [ϑ x] besitzen. Für solche Verteilungen werden (ein- und zweiseitige) Tests und Konfidenzintervalle mit gewissen Optimalit?tseigenschaften entwickelt, und zwar fürϑ, für die Differenzϑ ₁ −ϑ ₂, sowie für einige Versionen desk-Stichproben Problems. Sodann werden einige Hilfss?tze über den bedingten Erwartungswert und die bedingte Varianz von zweiparametrigen Verteilungen abgeleitet, die bezüglich des einen Parameters reproduktiv sind und eine bezüglich des zweiten Parameters ersch?pfende und vollst?ndige Funktion besitzen. Schlie?lich werden die allgemeinen Ergebnisse auf einige diskrete Verteilungen (Binomial, Poisson, negativ Binomial, Pascal) angewendet und der Zusammenhang mit verschiedenen bekannten Tests diskutiert.

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Summary Probability distributions are considered which (with respect to any measure) possess a density function of the typeC(ϑ) exp [ϑ x]. For distributions of this type (one and twosided) tests and confidence intervals with some optimal properties are given, namely forϑ, for the differenceϑ ₁ −ϑ ₂, and for several versions of thek-sample problem. Furthermore, some lemmas concerning the conditional expectation and the conditional variance are proved for two-parameter families of distributions which are reproductive in one parameter and possess a complete statistic, sufficient for the second parameter. Finally the general results are applied to some discrete distributions (binomial, Poisson, negative binomial, Pascal) and the relationship to several fairly known tests is discussed.

     

Ein Index zur numerischen Bestimmung der Niveau-Eigenschaft eines psychologischen Tests

Zusammenfassung Es wird ein Index definiert, der den Grad, in dem ein Intelligenz- oder Leistungstest die Eigenschaften und Bedingungen eines ideal-typischen Niveau-Tests erfüllt, kennzeichnet. Der Index variiert in den Grenzen von 0 bis 1, wobei der Wert 0 einem idealtypischen Schnelligkeitstest (Speed-Test) und der Wert 1 einem idealtypischen Niveau-Test entspricht. Dieser Index kann aufgrund einer einmaligen Testdurchführung bestimmt werden; er ist abh?ngig von der Zeitbegrenzung des Testes und vom Leistungsniveau der untersuchten Stichprobe. Es wird vorgeschlagen, einen Test mitw> > 0,7 als Niveautest, einen solchen mitw<0,3 als Schnelligkeitstest zu bewerten. Die Berechnung vonw wird an Hand bekannter Tests demonstriert und einige Anwendungsbeschr?nkungen er?rtert.

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Summary An index (w) for determining a test as to its degree of being a speed or a power test is proposed varying like a coefficient of correlation from zero to one. This index may be derived from a single testing a posteriori. It is dependent on the given time limit and on the achievement level of the sample tested. From empirical evidence it is suggested to accept a test with an indexw>0,7 as a power test and a test withw<0,3 as a speed test. Numerical examples for calculatingw are given and some restrictions for its application are discussed.

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Herrn Prof. H. Münzner (Berlin) danken die Verfasser für die Durchsicht des Manuskriptes und für seine wertvollen Anregungen.