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.     

Comparison of different estimation techniques for portfolio selection

The main problem in applying the mean-variance portfolio selection consists of the fact that the first two moments of the asset returns are unknown. In practice the optimal portfolio weights have to be estimated. This is usually done by replacing the moments by the classical unbiased sample estimators. We provide a comparison of the exact and the asymptotic distributions of the estimated portfolio weights as well as a sensitivity analysis to shifts in the moments of the asset returns. Furthermore we consider several types of shrinkage estimators for the moments. The corresponding estimators of the portfolio weights are compared with each other and with the portfolio weights based on the sample estimators of the moments. We show how the uncertainty about the portfolio weights can be introduced into the performance measurement of trading strategies. The methodology explains the bad out-of-sample performance of the classical Markowitz procedures.     

A bio-psycho-social model of successful aging as shown through the variable “physical activity”

In this article, we present and explain a bio-psycho-social model of successful aging with subjective well-being as a criterion of a successful aging process. We focus on physical activity because it is a crucial behavior. Physical activity can support successful aging in two different ways: first, due to its physiological and cognitive effects, and Second, an older person can enhance subjective well-being (SWB) while being physically active. The model points out that an older person can regulate SWB. To do this, an older person should set and pursue personally and culturally valued goals. The strength of the association between setting a goal and goal pursuance, respectively, and SWB depends on the extent a person is able to satisfy psychological needs (autonomy, competence, relatedness). But, the decision as to which goal will be set and pursued does not belong to the older person exclusively. The bio-psycho-social model explains that the chance to enhance SWB is restricted by personal dispositions (e.g., physiological constitution, psychological factors) and social–structural constraints (e.g., predominant stereotype of aging, facilities especially for target groups). Funding credit: Landesstiftung Baden Württemberg gGmbH [Landesstiftung Foundation]     

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.     

Economics of (oil) price politics: Penalizing price changes

This article studies intertemporal monopolistic pricing strategies when demand is dynamic and when price volatility may harm other producer objectives, e.g. the political good will for an international cartel. The major implications from this framework are that the introduction of a penalty for price changes may actually change an otherwise (at least locally) monotonic policy into a (transiently) oscillatory strategy; on the other hand, penalizing price changes smooths the price policy when demand is convex and the optimal strategy would otherwise be extremely volatile. But, then, all various types of solutions—cyclical and even unstable solutions—may occur.