A note on fourth moment-based direction dependence measures when regression errors are non normal

Measures of direction dependence enable researchers to determine the directionality of linear effects in bivariate data. Existing fourth moment-based approaches assume that regression errors are at least mesokurtic. Direction dependence measures based on the co-kurtosis of variables are proposed that relax this assumption. Simulations suggest that co-kurtosis-based measures perform equally well as existing kurtosis-based methods when distributional assumptions of the latter are fulfilled. However, kurtosis-based approaches are sensitive to platy- or leptokurtic errors, while co-kurtosis-based measures protect Type I error and power rates. Data requirements necessary for causal inference and recommendations for selecting proper direction dependence measures are discussed.     

Robust variable selection with application to quality of life research

A large database containing socioeconomic data from 60 communities in Austria and Germany has been built, stemming from 18,000 citizens’ responses to a survey, together with data from official statistical institutes about these communities. This paper describes a procedure for extracting a small set of explanatory variables to explain response variables such as the cognition of quality of life. For better interpretability, the set of explanatory variables needs to be very small and the dependencies among the selected variables need to be low. Due to possible inhomogeneities within the data set, it is further required that the solution is robust to outliers and deviating points. In order to achieve these goals, a robust model selection method, combined with a strategy to reduce the number of selected predictor variables to a necessary minimum, is developed. In addition, this context-sensitive method is applied to obtain responsible factors describing quality of life in communities.     

Arbeitsmarktforschung und Arbeitsmarktstatistik aus der Sicht der wirtschaftspolitischen Beratung: Erfahrungen und Perspektiven

Zusammenfassung: Dieser Beitrag beleuchtet aus der Sicht der wirtschaftspolitischen Beratung einige Anforderungen an die Arbeitsmarkt?konomik und Arbeitsmarktstatistik. Drei Bereiche werden angesprochen: die Arbeitslosenstatistik, die Tariflohnpolitik und die aktive Arbeitsmarktpolitik. Dabei werden zun?chst die Bemühungen hinsichtlich einer realistischeren Erfassung der Unterbesch?ftigung gewürdigt, zugleich aber Hinweise auf Verbesserungsm?glichkeiten gegeben. Anforderungen an die amtliche Statistik ergeben sich des Weiteren hinsichtlich der Tarifentgelte. In diesem Zusammenhang wird die Umsetzung der Erkenntnisse der Arbeitsmarkt?konomik in eine lohnpolitische Orientierungshilfe skizziert. Schlie?lich erfolgt eine kritische Einsch?tzung des Erfolgs der aktiven Arbeitsmarktpolitik, wobei eine zunehmende Willigkeit zur Bereitstellung der für die Evaluation erforderlichen Daten konstatiert werden kann.

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Summary: This paper deals with three demands on labor economics and labor statistics put forward from the point of view of an advisor to economic policy. Despite several improvements of unemployment statistics, a lot of work remains to be done. With respect to wage policy attempts by the German Council of Economic Experts are discussed how to formulate a guidance for wage policy both on scientific grounds and understandable by the public. Finally, a critical assessment of active labor market policies is presented together with a plea for adequate individual data in order to carry out a sound evaluation of these policies.

* Vortrag für die „Statistische Woche“, die Jahrestagung der Deutschen Statistischen Gesellschaft am 20. September 2004 in Frankfurt/Main. Der Vortragsstil wurde beibehalten. Die hier vorgetragenen Auffassungen liegen allein in der Verantwortung des Autors und stellen nicht notwendigerweise die Auffassungen anderer Institutionen dar. Ich danke Bernd Fitzenberger (Universit?t Frankfurt/Main und ZEW), Joachim M?ller (Universit?t Regensburg), Bernhard Boockmann und Tobias Hagen (ZEW), Irmtraud Beuerlein und Dirk Heinlein (Statistisches Bundesamt) für hilfreiche Kommentare und Anregungen. Verbleibende M?ngel gehen—leider—zu meinen Lasten.     

Abstimmungsprobleme in Dienstleistungsbeziehungen

In interactive service work customers necessarily take part in the service process as co-producers. Consequently, both the customers and the service workers are confronted with problems which can be conceived as social dilemmas. This article shows how these problems arise and how they can be solved. We analyze qualitative data on interactive service work using a rational action approach. The analysis shows that actors find themselves in dilemmatic situations, which would not allow them to achieve the optimal outcome of co-operation, if they would act according to the premises of the theory of rational action. On the other hand it is the interactive nature of co-production itself which not only generates social dilemmas but provides also for the means to resolve them: the mutual monitoring of the actions carried out by service worker and customer supplies them with informations about their willingness to co-operate. This may form the basis to overcome the social dilemmas inherent in service interaction.     

Root n consistent and optimal density estimators for moving average processes

Abstract.  The marginal density of a first order moving average process can be written as a convolution of two innovation densities. Saavedra & Cao [Can. J. Statist. (2000), 28, 799] propose to estimate the marginal density by plugging in kernel density estimators for the innovation densities, based on estimated innovations. They obtain that for an appropriate choice of bandwidth the variance of their estimator decreases at the rate 1/ n . Their estimator can be interpreted as a specific U -statistic. We suggest a slightly simplified U -statistic as estimator of the marginal density, prove that it is asymptotically normal at the same rate, and describe the asymptotic variance explicitly. We show that the estimator is asymptotically efficient if no structural assumptions are made on the innovation density. For innovation densities known to have mean zero or to be symmetric, we describe improvements of our estimator which are again asymptotically efficient.     

Regional economic stress as moderator of liability of foreignness

In this paper we develop optimized localization strategies for multinational firms to overcome their liability of foreignness by adding a regional dimension within a country. We explore conceptually whether economic stress in a region has a mitigating or reinforcing effect. We test this analytical framework empirically on the highly internationalized German car market and find that intra-national regions under economic stress are more promising markets for foreign car manufacturers as the effects of liability of foreignness are significantly lower there.