Christian Aßmann

Assessing the Effect of Current Account and Currency Crises on Economic Growth

Several empirical studies are concerned with measuring the effect of currency and current account crises on economic growth. Using different empirical models this paper serves two aspects. It provides an explicit assessment of country specific factors influencing the costs of crises in terms of economic growth and controls via a treatment type model for possible sample selection governing the occurrence of crises in order to estimate the impact on economic growth correctly. The applied empirical models allow for rich intertemporal dependencies via serially correlated errors and capture latent country specific heterogeneity via random coefficients. For accurate estimation of the treatment type model a simulated maximum likelihood approach employing efficient importance sampling is used. The results reveal significant costs in terms of economic growth for both crises. Costs for reversals are linked to country specific variables, while costs for currency crises are not. Furthermore, shocks explaining current account reversals and growth show strong significant positive correlation.

Modeling determinants of growth: evidence for a community-based target in height?

Background:Human growth is traditionally envisaged as a target-seeking process regulated by genes, nutrition, health, and the state of an individual’s social and economic environment; it is believed that under optimal physical conditions, an individual will achieve his or her full genetic potential.Methods:Using a panel data set on individual height increments, we suggest a statistical modeling approach that characterizes growth as first-order trend stationary and allows for controlling individual growth tempo via observable measures of individual maturity. A Bayesian framework and corresponding Markov-chain Monte Carlo techniques allowing for a conceptually stringent treatment of missing values are adapted for parameter estimation.Results:The model provides evidence for the adjustment of the individual growth rate toward average height of the population.Conclusion:The increase in adult body height during the past 150 y has been explained by the steady improvement of living conditions that are now being considered to have reached an optimum in Western societies. The current investigation questions the notion that the traditional concept in the understanding of this target-seeking process is sufficient. We consider an additional regulator that possibly points at community-based target seeking in growth.

Statistical agreement and cost–benefit: Comparison of methods for constructing growth reference charts

Abstract Background: Growth reference charts are important tools for adequate paediatric decisions. Aim: In view of the workload required to construct empirical growth reference charts we debate practicable and less demanding alternatives and took the recent national 2000–2002 Lithuanian growth charts as an example. Two options appeared reasonable: (1) applying international WHO child growth standards and WHO growth reference data for 5–19 years that are recommended for global use; or (2) replacing the costly empirical method of deriving national growth references by more convenient low-cost statistics, e.g. the method of generating synthetic references for the Lithuanian population. Methods: We analysed the degree of agreement between the 2000–2002 Lithuanian growth charts, and the international WHO child growth standards and WHO growth reference data for 5–19 years and synthetic references for the Lithuanian population using the Bland–Altman method. Results: Synthetically generated references for the Lithuanian population slightly surpassed the national Lithuanian reference for body height (males +0.3 (SD 0.9) cm; females +0.2 (SD 0.6) cm) particularly at young age, which may be regarded clinically irrelevant. WHO international child growth standards and the WHO growth reference data for 5–19 years, however, failed to match the Lithuanian references as they underestimated mean height in boys by –2.8 (SD 1.4) cm and in girls by –2.9 (SD 1.1) cm, with extremely discrepant estimates of more than –6 cm occurring in several adolescent cohorts. Conclusions: The analysis revitalizes the debate on clinically relevant and at the same time practicable but less demanding alternatives for constructing growth reference charts, and for economic reasons, strongly suggests replacing the traditional empirical methods by synthetic growth references.

Sex, Sport, IGF-1 and the Community Effect in Height Hypothesis

We test the hypothesis that differences in social status between groups of people within a population may induce variation in insulin-like growth factor-1(IGF-1) levels and, by extension, growth in height. This is called the community effect in height hypothesis. The relationship between IGF-1, assessed via finger-prick dried blood spot, and elite level sport competition outcomes were analysed for a sample of 116 undergraduate men and women. There was a statistically significant difference between winners and losers of a competition. Winners, as a group, had higher average pre-game and post-game IGF-1 levels than losers. We proposed this type of difference as a proxy for social dominance. We found no evidence that winners increased in IGF-1 levels over losers or that members of the same team were more similar in IGF-1 levels than they were to players from other teams. These findings provide limited support toward the community effect in height hypothesis. The findings are discussed in relation to the action of the growth hormone/IGF-1 axis as a transducer of multiple bio-social influences into a coherent signal which allows the growing human to adjust and adapt to local ecological conditions.

The impact of physical connectedness on body height in Swiss conscripts

BACKGROUND Human populations differ in height. Recent evidence suggests that social networks play an important role in the regulation of adolescent growth and adult height. We further investigated the effect of physical connectedness on height. MATERIAL AND METHODS We considered Switzerland as a geographic network with 169 nodes (district capitals) and 335 edges (connecting roads) and studied effects of connectedness on height in Swiss conscript from 1884 - 1891, 1908 - 1910, and 2004 - 2009. We also created exponential-family random graph models to separate possible unspecific effects of geographic vicinity. RESULTS In 1884 - 1891, in 1908 - 1910, and in 2004 - 2009, 1(st), 2(nd) and 3(rd) order neighboring districts significantly correlate in height (p < 0.01). The correlations depend on the order of connectedness, they decline with increasing distance. Short stature districts tend to have short, tall stature districts tend to have tall neighbors. Random network analyses suggest direct road effects on height. Whereas in 1884 - 1891, direct road effects were only visible between 1(st) order neighbors, direct road effects extended to 2(nd) and 3(rd) in 1908 - 1910, and in 2004 - 2009, also to 4(th) order neighbors, and might reflect historic improvements in transportation. The spatial correlations did not significantly change when height was controlled for goiter (1884 - 1889) and for median per capita income (2006), suggesting direct road effects also in goiter-allowed-for height and income-allowed-for height. CONCLUSION Height in a district depends on height of physically connected neighboring districts. The association decreases with increasing distance in the net. The present data suggest that people can be short because their neighbors are short; or tall because their neighbors are tall (community effect on growth). Psycho-biological effects seem to control growth and development within communities that go far beyond our current understanding of growth regulation.

Costs of Housing Crises: International Evidence

This paper analyzes the costs of housing crises in terms of GDP growth and the economic conditions under which crises are particularly costly. Housing crises are often followed by recessions that are longer than other recessions. According to empirical estimates, a housing crisis reduces the GDP growth rate in the following year on average by two percentage points and has still a considerable negative impact in the second year. One important channel through which the effect of housing crises is passed on seems to be the banking sector. In addition, our results suggest that negative wealth effects possibly cause further reductions in GDP.

Harmonizing national growth references for multi-centre surveys, drug monitoring and international postmarketing surveillance

Aim:  National European growth references differ. We aimed to convert (harmonize) currently used charts into a single unified interchangeable LMS format for each European nation.

The decline in German output volatility: a Bayesian analysis

Using Bayesian methods, we analyze whether a volatility reduction as documented for growth of U.S. gross domestic product (GDP) in the mid-1980s can also be detected for German GDP growth. Our analysis is based on different time series models allowing for alternative characterizations of output stabilization. Across all models we find empirical evidence for a decline in the output volatility around 1993. Furthermore, we assess competing explanations for reduced output volatility. Our empirical results suggest that the main source for the volatility reduction is an ongoing structural shift accelerated by the German reunification and accompanied by changes in the correlation structure between individual GDP components.

Synthetic growth reference charts

To reanalyze the between‐population variance in height, weight, and body mass index (BMI), and to provide a globally applicable technique for generating synthetic growth reference charts.

Determinants and Costs of Current Account Reversals Under Heterogeneity and Serial Correlation

Using large panel data sets for analysis of determinants and costs of reversals asks for controls of latent heterogeneity among countries. This article performs a Bayesian analysis, which allows for a parsimonious yet flexible handling of country specific heterogeneity via random coefficients and serially correlated errors. Consideration of persistence within the employed macroeconomic data is important to gauge the impact of explaining variables suggested by theory correctly. Bayesian specification tests provide evidence in favour of models incorporating heterogeneity and serial correlation. The results suggest that costs of reversals are overestimated, when country specific heterogeneity is neglected and stress the importance of external variables in explaining current account reversals. Results are checked for robustness against the underlying reversal definition.