Does the online collection of ego-centered network data reduce data quality? An experimental comparison

We analyze whether differences in kind and quality of ego-centered network data are related to whether the data are collected online or offline. We report the results of two studies. In the first study respondents could choose between filling out ego-centered data through a web questionnaire and being probed about their network in a personalized interview. The second study used a design in which respondents were allocated at random to either online or offline data collection. Our results show that the data quality suffers from the online data collection and the findings indicate that this is the consequence of the respondents answering “mechanically”. We conclude that network researchers should avoid to simply copy traditional network items into a web questionnaire. More research is needed about how new design elements specific for web questionnaires can motivate respondents to fill out network questions properly.     

Hiring older workers and employing older workers: German evidence

Using German establishment data, we examine the relationship between delayed compensation, training, and hiring of older workers. Both those establishments that delay compensation and those with greater human capital requirements are less likely to hire older workers. We demonstrate that the routinely used control for the age of existing workers is endogenous and that instrumenting provides stronger evidence for the role of delayed compensation. Specifically, delayed compensation is simultaneously a negative determinant of hiring older workers but a positive determinant of employing older workers and, thus, more clearly associated with “employing older workers but not hiring them.”     

Health and economic development—evidence from the introduction of public health care

This paper investigates the causal effect of improvements in health on economic development using a long panel of European countries. Identification is based on the particular timing of the introduction of public health care systems in different countries, which is the random outcome of a political process. We document that the introduction of public health care systems had a significant immediate effect on health dynamics proxied by infant mortality and crude death rates. The findings suggest that health improvements had a positive effect on growth in income per capita and aggregate income.     

Transnationale Projektarbeit. Berufsbiografische Strategien der Sicherung von Autonomie, Zugehörigkeit und Identität

The article intends to broaden the discussion about the globalization of management by analyzing an intermediate, operative level of management in the context of transnational project work. In contrast to Kanter’s (1996) thesis of the emergence of a “world class of management” the identity concepts, career strategies and social embeddedness of this level of management clearly show the contradictions and ambivalences peculiar to this kind of work. Drawing on group discussions as well as problem-centred interviews three types of biography politics in the context of transnationalization are discerned. By more or less intentionally unfolding these politics in the course of their biographies, the subjects are struggling for autonomy, affiliation and individual history.     

Subjective and objective evaluation of sense of space for vehicle occupants based on anthropometric data

At present, the number of the vehicle requirements has been continuously increasing. These requirements can be related to the customer as well as the technical requirements. Among these, the "feeling of space" of the occupants inside the vehicles can be regarded as one of the most important factors. In this respect, the driver and passengers should be able to experience positive feeling of space inside the vehicle. There are numerous factors that can influence the sense of space inside the vehicle. These include geometry (vehicle dimensions), light exposure, ambient lights, colors, material selection and material surface. Depending on the selection, the sense of space can be dramatically influenced by these factors. In general, human feeling is subjective and cannot be measured by any instrument. The measure can nevertheless be carried out by utilizing the method of subjective evaluation. Throughout the experiments, the method of evaluation is developed and the factors which can influence the interior feeling are analyzed. In this process, psychological perception, architectural aspects and anthropometry are considered and knowledge from the other domains is transferred in the form of a multidisciplinary approach. The experiments with an aim to evaluate the overall sense of space in the vehicle are carried out based on the physical mock up of BMW 1 series (E87). The space perception with different interior dimensions and anthropometric data of test persons are also analyzed. The use of Computer Aided Technology was shown by CATIA V5, PCMAN and RAMSIS. The results show a good correlation between the subjective evaluation and the geometric values.     

Effect of neglected deterministic seasonality on unit root tests

Whenever deterministic seasonality is ignored, the distribution of the Dickey-Fuller test is shifted to the left, with lower dispersion at the same time. When accounting for serial correlation, the distortions become less predictable. A Monte Carlo study confirms that the (augmented) Dickey-Fuller test without seasonal dummies is oversized and has little power at the same time, due to the need of lag augmentation. The effect of neglecting seasonal deterministics on the KPSS test for stationarity depends on the way the long-run variance is estimated. This is a shorter version of a working paper containing additional experimental evidence and the proofs of the propositions. The working paper is available online under http://www.wiwi.uni-frankfurt.de/~deme/ends_urt.pdf.