Risedronate, the BBC and me

Risedronate is a drug used to reduce fractures in women with osteoporosis. The story of the Sheffield Risedronate trial made national news when one of the clinical researchers, Aubrey Blumsohn, dissociated himself from the trial because he was refused access to the data he had helped to collect. Later, some of that data turned up. Here Martin Bland describes how he came to analyse the data on behalf of the BBC, what he found and what happened next.     

Produktdiversifizierung und Unternehmenserfolg: Nutzung der Forschungsdatenzentren der Statistischen ?mter

Zusammenfassung: Im Rahmen seiner industrie?konomischen Forschung beabsichtigt das DIW Berlin das Verhalten von Unternehmen auf den Produktm?rkten intensiver zu analysieren. In einem ersten Schritt soll der Zusammenhang zwischen Produktdiversifizierung, der Einführung neuer Produkte und dem Erfolg von Unternehmen im verarbeitenden Gewerbe untersucht werden. Dies soll mit Hilfe einer ?konometrischen Panelanalyse auf der Grundlage von Mikrodaten von Unternehmen erfolgen. Statt des in der Arbeitsmarktforschung üblichen Employer-Employee Datensatzes wird für diesen Zweck ein Producer-Product Datensatz ben?tigt. Erstmals sollen diese Mikrodaten im Rahmen einer Panelanalyse durch die Forschung ausgewertet werden. Dabei werden zwei getrennt durchgeführte Erhebungen, die Kostenstrukturerhebung und die Produktionserhebung, für einzelne Unternehmen zusammengefasst. M?glich wird dieses Forschungsvorhaben durch die Nutzung des auf Empfehlung der Kommission zur Verbesserung der informationellen Infrastruktur neu eingerichteten Forschungsdatenzentrums (FDZ). Das vorliegende Papier berichtet über das Forschungskonzept und die bisher erfolgten Schritte bei der Nutzung der Forschungsdatenzentren des Bundes und der L?nder am regionalen Standort Berlin.

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Summary: For a better understanding of the strategies of firms on their product markets, the DIW Berlin intends to intensify the analysis on the relationship between product diversification, including the introduction of new products and the success of firms. It is planned to do this by applying econometric panel methods on micro level data for German manufacturing enterprises. For this objective, it is necessary to create a producer-product database. This affords the merging of two different datasets of the system of surveys in manufacturing for Germany. The cost structure survey supplies information on the operating surplus of individual firms, while the production survey supplies the information on the goods produced by these firms. Conducting such an ambitious project has now been made possible in using the newly installed Research Data Centres (FDZ) for Germany. This paper gives an overview on the research project and on first experiences with the use of the local Research Data Centre in Berlin.

     

Arbeitsmarkt und Statistik: Chancen und Herausforderungen für die empirische Arbeitsmarktforschung

Ohne Zusammenfassung     

On repeated measures analysis with misspecified covariance structure

In recent years various sophisticated methods have been developed for the analysis of repeated measures, or longitudinal data. The more traditional approach, based on a normal likelihood function, has been shown to be unsatisfactory, in the sense of yielding asymptotically biased estimates when the covariance structure is misspecified. More recent methodology, based on generalized linear models and quasi-likelihood estimation, has gained widespread acceptance as 'generalized estimating equations'. However, this also has theoretical problems. In this paper a suggestion is made for improving the asymptotic behaviour of estimators by using the older approach, implemented via Gaussian estimation. The resulting estimating equations include the quasi-score function as one component, so the methodology proposed can be viewed as a combination of Gaussian estimation and generalized estimating equations which has a firmer asymptotic basis than either alone has.     

Determinanten des Wiedereinstiegs von Müttern in den Arbeitsmarkt in Vollzeit oder Teilzeit

This paper deals with the question which determinants influence the re-entry of mothers on the labor market after the first childbirth. Contrary to existing studies it is possible to distinguish empirically between full time and part time employment after re-entry by employing the newly available BASiD-data. Theoretical arguments indicate that women decide deliberately for a part or full time job due to labor market restriction, their household und family situation and institutional rules which vary in time. Empirically this paper focuses on mothers in West Germany because the data includes a long observation period before reunification. Based on event history models we can show that the determinants for full and part time re-entries differ substantially. Hence it can be reasoned that full and part time jobs for re-entry after birth are not simple substitutes for the women.     

Designing computer models that work

The techniques of financial modelling are becoming more popular and accepted as a useful information processing tool. However, what is ‘financial modelling’ and does the term adequately describe current applications? Why has financial modelling been such a growth area and what are the benefits? Given a desire to build models, where does the manager begin? What type of system and language should be used and by whom? What type of computing facility is most suitable? Which modelling system should be selected and what features are important? As well as an increase in the number of financial modelling applications they are now more complex. What guidelines can one use when designing large and complex models? This article seeks to answer these questions, concentrating on the large and more complex models, particularly for long term planning and budgeting applications. Finally an example is given illustrating how a large modelling system can be constructed and maintained with little technical computer expertise.