Beneficial safety decreases

We construct a model of rational choice under risk with biased risk judgement. On its basis, we argue that sometimes, a regulator aiming at maximising social welfare should affect the environment in such a way that it becomes ‘less safe’ in common perception. More specifically, we introduce a bias into each agent’s choice of optimal risk levels: consequently, in certain environments, agents choose a behaviour that realises higher risks than intended. Individuals incur a welfare loss through this bias. We show that by deteriorating the environment, the regulator can motivate individuals to choose behaviour that is less biased, and hence realises risk levels closer to what individuals intended. We formally investigate the conditions under which such a Beneficial Safety Decrease—i.e. a deteriorating intervention that has a positive welfare effect—exists. Finally, we discuss three applications of our model.     

Variance bounds for estimators in autoregressive models with constraints

We consider nonlinear and heteroscedastic autoregressive models whose residuals are martingale increments with conditional distributions that fulfil certain constraints. We treat two classes of constraints: residuals depending on the past through some function of the past observations only, and residuals that are invariant under some finite group of transformations. We determine the efficient influence function for estimators of the autoregressive parameter in such models, calculate variance bounds, discuss information gains, and suggest how to construct efficient estimators. Without constraints, efficient estimators can be given by weighted least squares estimators. With the constraints considered here, efficient estimators are obtained differently, as one-step improvements of some initial estimator, similarly as in autoregressive models with independent increments.     

Entscheidungsverhalten von Kunden in Mass Customization-Systemen

Sequential choice processes are ubiquitous in consumer decision making. In each attribute decision, consumers are often faced with different numbers of options which they must trade off in order to make the best possible choice. Thereby, complicated high variety choices at the beginning of a choice process produce a larger trade-off conflict and, thus, initially a greater mental depletion than more simple low variety choices. We examine the strength of mental depletion in sequential choices on individuals’ perceived attractiveness of the firm’s recommended default option at a target choice. We show that consumers who are confronted with difficult high variety choices early in the decision sequence followed by low variety choices initially deplete more than consumers who encounter exactly the same attribute decisions in reverse. As a result, depleted consumers are more likely to fall prey to the recommended default or some perceptually focal options close to the default anchor at target choice succeeding a sequence of decisions.     

„Zu allem fähig“

Ohne Zusammenfassung     

Sind Universitätsprüfungen objektiv?

In diesem Beitrag werden Ergebnisse aus einem quantitativ-historischen Forschungsprojekt vorgestellt, die es zulassen, die provokative Titelfrage nach der Objektivit?t von akademischen Prüfungen in der Zeit bis 1945 zu stellen. Die Objektivit?t wird dadurch in Frage gestellt, dass die Quoten des Nicht-Bestehens in universit?ren und nach-universit?ren Abschlussprüfungen systematisch im Zeitverlauf stiegen und fielen, und zwar im Rhythmus der Arbeitsmarktchancen der jeweiligen Karrieren, die mit dem Studienfach verbunden sind: In Zeiten von überfüllung in den Karrieren bestanden prozentual mehr Kandidaten die Prüfungen nicht. Ein m?glicher Grund sind ?nderungen des „Selektionsklimas“ im Bildungssystem. Dieser Zusammenhang k?nnte auch nach 1945 bis heute weiterbestanden haben, obwohl die bisher schlechte Datenlage hier keine generelle Aussage zul?sst.     

Prediction of temporally aggregated systems involving both stock and flow variables

Two predictors for a system of temporally aggregated variables are discussed. One predictor is based on the disaggregated variables whereas the other one uses only information contained in the aggregates. In contrast to similar research on the topic it is explicity assumed that the system involves both stock and flow variables. It is shown that some results obtained by treating the two types of variables separately break down if the system contains both. In particular, equality of the two predictors under investigation holds only under extremely restrictive conditions in the latter case. The paper was presented at the European Meeting of the Econometric Society 1988 in Bologna.     

Wer erbt Mehr? Erbschaften, Sozialstruktur und Alterssicherung

How do inheritances affect social structure, wealth formation, and provision for old age? Who benefits the most from inheritances? We analyse these questions based on the 2001 wave of the Socio-Economic Panel, which gives information on the deceased, and on the type, time, chance, and amount of the inheritance. Our findings confirm the theoretical hypotheses in general. Inheritance research is intergenerational research: most inheritances come from parents and benefit the recipients in the second half of their lives. However, the chances of receiving an inheritance and amounts inherited are distributed very unevenly. West Germans inherit significantly more frequently and larger amounts than East Germans due to the continuing effects of conditions in the former GDR. Foreigners have particularly low chances of receiving an inheritance. Thus, provision for old age through inheritance is limited mainly to specific groups of people. The most advantaged groups are the highly educated classes, which already receive higher (retirement) income.     

Grenzen der Geschichte?

The article follows Tony Becher’s suggestion, that scientific disciplines metaphorically spoken may be looked at as different tribes of different habits occupying different territories. The articles reviews then some possibilities to determine a border between the field of historical research and sociology by different methods, different theories, different research objects e. g. past vs. present and so on. The academic field of history is described as a field importing theories, methods and objects from other academic fields, many of them from sociology. The last decades’ processes of innovation and redefinition within the field of historical research diminished cognitive differences between history and sociology so significantly that — this is the main argument of the article — more or less only the borders produced by institutions remained. Nevertheless these kind of borders have major effects all of them responsible for maintaining different disciplinary identities.