„Analysis of Categorical Data and Discrete Choices“ 30. Frühjahrsseminar des Zentralarchivs für Empirische Sozialforschung Universität zu Köln, 5.–23. März 2001

Ohne Zusammenfassung     

低生育水平下中国人口规模与年龄结构的变化

本文借助一些机构对21世纪中叶中国人口变化的预测 ,就未来50年低生育水平对中国人口规模和年龄结构的影响进行了初步的分析     

Trends in the association between educational attainment and class destinations in West Germany: Looking inside the service class

The paper investigates long-term trends in the association between educational attainment and class destinations in Germany. Most recent evidence for several European countries reveals a downward effect of education on social class. To test changes in the association in Germany I use the 1976–2007 waves of the German Microcensus (GMC), which is a nationally representative, repeated cross-sectional survey. For Germany, log-linear models indicate that the relationship between education and class destinations remains rather constant for both sexes. I also find that returns to higher education in access to service class positions do not consistently decline either. Only university graduates’ relative access chances slightly decreased in comparison to Abitur-holders from the 1980s to the 1990s. In order to consider compositional changes in the service class in more detail, I further disaggregate the service class into three types of employment: administrative/managerial positions, professional experts and professional positions in the social services. In fact, I find that access to administrative and managerial positions is less dependent on education than access to the professions. While professional positions in the social services become less stratified by education over time, it is compensated by a reverse development for professional experts. As substantially more employees work in administrative and managerial jobs since the 1970s, the slight reduction in university returns can indeed be attributed to a compositional effect. In spite of these qualitative and quantitative changes, the strong impact of education on access to the service class does not become blurred. The paper concludes that the persistent institutional framework in Germany does not lead to a decline in the overall association between educational attainment and class destinations.     

Kooperation unter Konkurrenten? Regionale Kulturmuster und soziale Praktiken betriebsübergreifender Personalwirtschaft

During the recent financial and economic crisis, trade unions and employers’ associations have increasingly concluded collective agreements on so-called “collegial temporary work” that enables flexible deployment of employees, especially for small and medium sized enterprises. Empirical results show large differences in the application of those collective agreements: While the possibilities of the agreements were sometimes actively used in some regions, companies in other regions avoided implementation – despite their potential to cope with important challenges of economic crises and skill shortages. The paper selects a structuration theory perspective to analyze the reasons for the differences in the practice of this human resource management strategy by comparing two German regions (Braunschweig and the Ruhr area). The differences in the practices can be traced back to regional cultural patterns, interests of key actors, and the degree of involvement during the implementation period.     

Verarmungsrisiken nach kritischen Lebensereignissen in Deutschland und den USA

We study how the impact of job loss, sickness, retirement, and family dissolution on the risk of relative income poverty differs between Germany and the United States, and whether the impact of these events has changed between 1980 and 2009. Americans are more likely than Germans to enter poverty after any of the four events, yet they also recover more quickly from job loss and family dissolution. Comparisons over time do not indicate a secular rise in the impact of critical life events on poverty risks, but our results show that poverty trajectories are subject to stronger cyclical fluctuations in the United States: Through its emphasis on market mechanisms, the liberal American welfare state raises the importance of (re-)employment opportunities for coping with the consequences of adverse life events. The absence of clear long-term trends leads to a reassessment of common views about welfare state change such as Jacob Hacker??s thesis of a ??Great Risk Shift?? or the notion of an ??Americanization?? of Continental European welfare states. So far, there is also little evidence that the often claimed recalibration of welfare states towards ??new social risks?? has alleviated the adverse economic consequences of family dissolution.     

The new ‘sustainable communitarian’ logging schemes and their critique inside multiple-use conservation areas in the Brazilian Amazon: preliminary notes

Deforestation has risen sharply in Brazil since 2012, and conservation areas are facing increased pressure. This article studies the rise of so-called ‘sustainable’, ‘communitarian’, and/or ‘cooperative’ logging schemes inside multiple-use conservation areas in the Amazon. The findings, based on fresh field research in Acre and Pará, reveal conflicts, problems, and risks associated with logging schemes, although they are portrayed in the international timber trade as certified and socio-environmentally sustainable solutions that help conservation. However, the expansion of logging presents a danger for curtailing forest degradation, fires, and corruption that is linked to the fast returns from sale of timber, especially inside conservation areas that have been mostly intact until now. There is an urgent need to change the strategy of promoting logging as a key source of income for forest-dwellers, and a need to change the policies allowing the expansion of ‘sustainable logging’.     

Practical statistical considerations for investigating anti-tumor treatments in mice

Anti-tumor treatment outcomes in mouse experiments can be challenging to interpret and communicate accurately. In reporting these experiments, rigorous statistical considerations are commonly absent, although statistical applications have been proposed. We investigated the practicality and utility of different statistical strategies for the analysis of anti-tumor responses in a longitudinal mouse case study. Each analysis that we performed had different endpoints, investigated different questions, and was based on different assumptions. We found rudimentary visual and risk analysis insufficient without additional considerations, and upon further investigation we found improvements in key anti-tumor parameter estimates associated with a drug combination in our case study. We offer practical statistical considerations for investigating anti-cancer treatments in mice, applying a multi-tier statistical approach.     

Mean-Minimum Exact Confidence Intervals

This article introduces mean-minimum (MM) exact confidence intervals for a binomial probability. These intervals guarantee that both the mean and the minimum frequentist coverage never drop below specified values. For example, an MM 95[93]% interval has mean coverage at least 95% and minimum coverage at least 93%. In the conventional sense, such an interval can be viewed as an exact 93% interval that has mean coverage at least 95% or it can be viewed as an approximate 95% interval that has minimum coverage at least 93%. Graphical and numerical summaries of coverage and expected length suggest that the Blaker-based MM exact interval is an attractive alternative to, even an improvement over, commonly recommended approximate and exact intervals, including the Agresti–Coull approximate interval, the Clopper–Pearson (CP) exact interval, and the more recently recommended CP-, Blaker-, and Sterne-based mean-coverage-adjusted approximate intervals.     

Using crushed waste bricks for urban greening with contrasting grassland mixtures: no negative effects of brick-augmented substrates varying in soil type,moisture and acid pre-treatment

Ecological restoration aims at supporting biodiversity and ecosystem services, and urban greening is a great opportunity to achieve this goal. This is facilitated by species-rich seed mixtures based on local provenances, which are designed for certain nutrient and moisture regimes based on functional plant traits. Such grassland mixtures might be cultivated on crushed waste bricks, which would be a new component of water-holding urban substrates. Thus, we studied the effects of brick quantity and quality, acid pre-treatment of bricks, soil type and moisture on biomass of designed seed mixtures. Three greenhouse experiments were conducted, with substrates consisting of different brick ratios (5% vs. 30%), brick types (clean production waste vs. demolition material), and brick treatments (acid vs. control) tested on three trait-based mixtures and a non-regional commercial standard mixture. The trait-based mixtures included information on specific leaf area, seed mass and grass-to-legume ratio. There were no negative effects of demolition bricks, soil texture and moisture on grassland biomass. Acid-treated clean porous bricks improved biomass production of the standard and intermediate mixtures, while the effect was minimal with demolition bricks. Designed seed mixtures had a biomass similar to the standard mixture under dry conditions but did not benefit from high moisture like the standard mixture. In conclusion, waste bricks are a useful additive for urban restoration substrates to save raw material, and specifically designed regional mixtures can replace commercial grassland types on these substrates.