Exposition verhindern

Allergie durch Latex produkte - Nicht nur Pflegekr?fte leiden bisweilen an einer Latexallergie, auch Patienten k?nnen betroffen sein. Gerade bei Operationen, wenn latexhaltige Handschuhe, Katheter oder Beatmungsmasken direkten Kontakt zu Blut und Schleimh?uten des Patienten haben, ist das Risiko für Komplikationen hoch. Um schwerwiegende Notf?lle zu vermeiden, hilft oft nur eines – jegliche Latexexposition zu unterbinden.     

Class-size effects in school systems around the world: Evidence from between-grade variation in TIMSS

We estimate the effect of class size on student performance in 11 countries, combining school fixed effects and instrumental variables to identify random class-size variation between two adjacent grades within individual schools. Conventional estimates of class-size effects are shown to be severely biased by the non-random placement of students between and within schools. While we find sizable beneficial effects of smaller classes in Greece and Iceland, we reject the possibility of even small effects in four countries and of large beneficial effects in an additional four countries. Noteworthy class-size effects are observed only in countries with relatively low teacher salaries.     

Sectoral and aggregate estimates of the cyclical behavior of markups: Evidence from Germany

Sectoral and Aggregate Estimates of the Cyclical Behavior of Mark-ups: Evidence from Germany. — The paper presents evidence of the cyclical behavior of the price to marginal cost ratio for Germany. Average markups are estimated both for two-digit manufacturing industries and for the aggregate economy, the results being quite similar once the difference between gross output and and value-added markups is accounted for. Over the business cycle, markups appear to be countercyclical for most parameter constellations. This is interpreted as empirical support for business cycle theories that rely on aggregate demand shocks to affect markups inversely, thus producing procyclical real wages and productivity without having to assume technology shocks.     

The effect of Protestantism on education before the industrialization: Evidence from 1816 Prussia

Across Prussian counties and towns, Protestantism led to more schooling already in 1816, before the Industrial Revolution. This supports a human capital theory of Protestant economic history and rules out a Weberian explanation of Protestant education just resulting from industrialization.     

Tying governments' hands in commodity taxation

In the 1970s, taxation of 'windfall' profits from primary productsand intervention in trade and production tempted governmentsinto expansionary fiscal policies, whilst stifling the privatesector and depressing growth. However, the experience of themid-1990s coffee boom has so far been more favourable: thoseAfrican countries which liberalised and left a large share ofthe 'windfall' with the private sector, and which committedthemselves to fiscal austerity via adjustment programmes, haveshown better results in terms of fiscal stability, private sectorresponses and economic growth than countries which did not reform.These findings suggest that constraints on discretionary governmentpolicies are desirable, and that domestic institutions and internationalcommitments could serve this purpose.     

Model uncertainty and VaR aggregation

Despite well-known shortcomings as a risk measure, Value-at-Risk (VaR) is still the industry and regulatory standard for the calculation of risk capital in banking and insurance. This paper is concerned with the numerical estimation of the VaR for a portfolio position as a function of different dependence scenarios on the factors of the portfolio. Besides summarizing the most relevant analytical bounds, including a discussion of their sharpness, we introduce a numerical algorithm which allows for the computation of reliable (sharp) bounds for the VaR of high-dimensional portfolios with dimensions d possibly in the several hundreds. We show that additional positive dependence information will typically not improve the upper bound substantially. In contrast higher order marginal information on the model, when available, may lead to strongly improved bounds. Several examples of practical relevance show how explicit VaR bounds can be obtained. These bounds can be interpreted as a measure of model uncertainty induced by possible dependence scenarios.     

DYNAMIC CDO TERM STRUCTURE MODELING

This paper provides a unifying approach for valuing contingent claims on a portfolio of credits, such as collateralized debt obligations (CDOs). We introduce the defaultable (T, x) ‐bonds, which pay one if the aggregated loss process in the underlying pool of the CDO has not exceeded x at maturity T, and zero else. Necessary and sufficient conditions on the stochastic term structure movements for the absence of arbitrage are given. Background market risk as well as feedback contagion effects of the loss process are taken into account. Moreover, we show that any exogenous specification of the volatility and contagion parameters actually yields a unique consistent loss process and thus an arbitrage‐free family of (T, x) ‐bond prices. For the sake of analytical and computational efficiency we then develop a tractable class of doubly stochastic affine term structure models.     

Copula dynamics in CDOs

Values of tranche spreads of collateralized debt obligations (CDOs) are driven by the joint default performance of the assets in the collateral pool. The dependence between the entities in the portfolio mainly depends on current economic conditions. Therefore, a correlation implied from tranches can be seen as a measure of the general situation of the credit market. We analyse the European market of standardized CDOs using tranches of the iTraxx index in the periods before and during the global financial crisis. We investigate the evolution of the correlations using different copula models: the standard Gaussian, the NIG, the double-t, and the Gumbel copula model. After calibration of these models, one obtains a time varying vector of parameters. We analyse the dynamic pattern of these coefficients. That enables us to forecast future parameters and consequently calculate Value-at-Risk measures for iTraxx Europe tranches.     

Western industrial countries: brighter economic outlook,but world economy not out of the woods yet

Western industrial countries: brighter economic outlook, but world economy not out of the woods yet     

Semi‐analytic Approaches to Collateralized Debt Obligation Modelling

Collateralized debt obligations (CDOs) constitute an important class of asset‐backed securities. Most major banks use CDOs as portfolio management tools for achieving regulatory capital relief, economic risk transfer and funding. On the other side, banks and other financial institutions invest in CDO tranches with a risk/return profile matching their risk appetite and investment policies. For both sides (risk selling and risk buying) of a CDO transaction, sound mathematical tools are required for an evaluation of the deal. In this paper, we investigate some techniques for CDO modelling, paying special attention to approaches based on semi‐analytic approximations.