The Transition to Post-industrial BMI Values among US Children
Marco Sunder, Ariane Breitfelder, John Komlos
American Journal of Human Biology,
2009
Abstract
The trend in the BMI values of US children has not been estimated very convincingly because of the absence of longitudinal data. Our objective is to estimate time series of BMI values by birth cohorts instead of measurement years. We use five regression models to estimate the BMI trends of non-Hispanic US-born black and white children and adolescents ages 2-19 between 1941 and 2004. The increase in BMIZ values during the period considered was 1.3 (95% CI: 1.16; 1.44) among black girls, 0.8 for black boys, 0.7 for white boys, and 0.6 for white girls. This translates into an increase in BMI values of some 5.6, 3.3, 2.4, and 1.5 units, respectively. While the increase in BMI values started among the birth cohorts of the 1940s among black girls, the rate of increase tended to accelerate among all four ethnic/gender groups born in the mid-1950s to early-1960s. Some regional evidence leads to the conjecture that the spread of automobiles and radios affected the BMI values of boys already in the interwar period. We suppose that the changes in lifestyle associated with the labor saving technological developments of the 20th century are associated with the weight gains observed. The increased popularity of television viewing was most prominently associated with the contemporaneous acceleration in BMI gain. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc.
Read article
Von der Rendite zum Ballast - Der Einfluss der Demographie auf die wirtschaftliche Entwicklung
Lutz Schneider
Ordnungspolitische Standpunkte zu aktuellen Fragen der Umwelt-, Wettbewerbs- und Wirtschaftspolitik,
2008
Abstract
On the basis of a neoclassical production function in a small open economy the contribution shows potential economic effects of population and workforce ageing and shrinking. Some evidence is provided, that ageing and not shrinking is the true burden of demographic change.
Read article
Incubator Age and Incubation Time: Determinants of Firm Survival after Graduation?
Michael Schwartz
IWH Discussion Papers,
No. 14,
2008
Abstract
On the basis of a sample of 149 graduate firms from five German technology oriented business incubators, this article contributes to incubator/incubation literature by investigating the effects of the age of the business incubators and the firms’ incubation time in securing long-term survival of the firms after leaving the incubator facilities. The empirical findings from Cox-proportional hazards regression and parametric accelerated failure time models reveal a statistically negative impact for both variables incubator age and incubation time on post-graduation firm survival. One possible explanation for these results is that, when incubator managers become increasingly involved in various regional development activities (e.g. coaching of regional network initiatives), this may reduce the effectiveness of incubator support and therefore the survival chances of firms.
Read article
Demographic Change and Labour Markets: Why are Older Employees less Mobile?
Lutz Schneider
Wirtschaft im Wandel,
No. 10,
2008
Abstract
Since older workers are less disposed to change jobs workforce ageing will affect labour mobility in Germany. On the basis of the IAB-Employment Sample (IABS) the contribution analyzes the effect of age on job and occupational mobility. The study focuses on the question whether older workers are less mobile due to the optimal matching quality of their current job which cannot be improved by job switches or whether other factors have to be considered for explaining the age related mobility decline.
Econometric results firstly confirm the significance of expected wage growth for mobility decision across all age groups. Secondly, older workers seem to benefit from wage increase due to a job change less frequently than younger workers. However, this factor explains only a part of the mobility lag. Even after controlling for the wage effect younger workers change jobs more often than older ones.
For this reason the opinion that ageing will impede the labour market adjustments cannot be disabled. If older workers only slightly react on wage signals and do not respond to attractive offers growing firms might face problems to recruit appropriate staff – a trend which could have negative consequences for technological and sectoral changes of the entire economy.
Read article
Metformin-Therapie bei PCO-Syndrom - Positive Vierjahresbilanz des oralen Antidiabetikums
D. Albrecht, P. Kaltwasser, E. Rosenkranz, Dirk Trocka
MedReview,
2007
Abstract
The Polycystic ovary syndrome (PCOS) is the most frequent endocrinal disease of women in child-bearing age. PCOS represents a high risk for infertility, metabolic and cardiovascular diseases. This article analyses the outcomes after four years of PCOS-treatment with Metformin, an orally administered medication. We describe under which circumstances Metformin treatment is useful.
Read article
Alterung und technologisches Innovationspotential. Eine Linked Employer-Employee Analyse
Lutz Schneider
Zeitschrift für Bevölkerungswissenschaft,
No. 1,
2008
Abstract
Growth in advanced economies is essentially driven by innovation activities. The question rises from a demographic point of view as to whether the trend of an ageing workforce will affect the innovation capacities of these economies. To answer this question, the paper examines on the basis of a German linked-employer-employee-dataset whether an older workforce lowers a firm’s potential to generate product innovations. The empirical approach is based on an Ordered-logit regression model, relating a firm’s innovation potential to the age composition of its employees. The analysis provides evidence of significant age effects. The estimated age-innovation-profile follows an inverted U-shaped pattern, it peaks at the age of about 40 years. A separate estimation shows that technicians and engineers age seems to be particularly relevant.
Read article
Shrinking due to corpulence? BMI in childhood predicts subsequent linear growth among US children and youth, 1963-1970
Marco Sunder
Annals of Human Biology,
2008
Abstract
While the USA is one of the most opulent countries, its population is not among the tallest but is among the most corpulent. This short report investigates the association between body mass index in childhood and subsequent change in height-for-age at the individual level, based on data from the National Health Examination Study (1963-1970). A sub-sample of participants in this survey was measured twice at intervals between 2.3 and 4.4 years, and assessed bone age can be used to account for differences in maturation at baseline. Regression results indicate that a BMI-for-age above the 85th percentile is associated with a reduction in growth by 0.03-0.06 height-for-age standard deviations per year, or roughly 1 cm within 4 years. An inefficiently high nutritional status in childhood may thus jeopardize subsequent linear growth. However, the trans-Atlantic height gap is considerably larger than what this empirical relationship could predict.
Read article
Export Promotion Needs the Disclosure of Industrial Potentials – A Case Study for the Federal State of Thuringia
Udo Ludwig, Brigitte Loose, Cornelia Lang
Wirtschaft im Wandel,
No. 5,
2008
Abstract
In countries and regions with weak domestic markets, the orientation towards external markets plays an important rule. This applies even more for economies emerging from the transformation process from a state to a market economy with a small export sector and a continuous decline in the number of residents. The federal state Thuringia presents such an example. There is still a large gap in exports compared to Germany as a whole. The paper deals with the role of exports in economic development and economic measures to increase the export activities of small and medium-sized companies (SMEs) in Thuringia. The study is based on a survey among SMEs in Thuringia on the performance of exporters and non-exporters. One of the main findings shows that export promotion was important only for one among three exporting companies during the last three years. That speaks for the confidence of the firms in their own power. The most measures used to implement or advance export activities are participation in a fair, information sessions on foreign markets and two general instruments to support companies: investment and innovation stimulation. As a result, economic measures make sense, but it should not depend on the age or the size of a company. Besides, the support should not only be given by department of foreign trade, but also by other departments. Finally, especially newcomers should be supported to entry foreign markets.
Read article
In Focus: Migration Behaviour of East Germans
Alexander Kubis, Lutz Schneider
Wirtschaft im Wandel,
No. 4,
2008
Abstract
During the transition period, East Germany faced a strong out-migration towards the western part of Germany. Between 1989 and 2006, the net loss of internal migration in East Germany accumulated to 1.7 million people. Regarding the age distribution of these internal migration flows, it is shown that the net losses are primarily – over 50% – caused by young people aged 18 to 30 years. Besides the most important trend of East-West-migration, substantial regional differences can be observed. In the 1990s, the surrounding areas of large cities in East Germany benefited from suburbanisation. Afterwards, this trend has come to an end so that agglomerations in East Germany currently experience in-migration. However, peripheral regions faced strong negative net migration rates during the entire transition period.
Read article