The paper provides an axiomatic characterization of dynamic risk measures for multi-period financial positions. For the special case of a terminal cash flow, we require that risk depends on its conditional distribution only. We prove a representation theorem for dynamic risk measures and...

Rare and randomly occurring events are important features of the economic world. In continuous time they can easily be modeled by Poisson processes. Analyzing optimal behavior in such a setup requires the appropriate version of the change of variables formula and the Hamilton-Jacobi-Bellman...

We derive approximate formulae for the credit value-at-risk and the economic capital of a large credit portfolio. The representation allows to change the risk horizon quickly and avoids simulation or numerical procedures. The Poisson mixture model is equivalent to CreditRisk and uses the same...

Most credit portfolio models exclusively calculate the loss distribution for a portfolio of performing counterparts. Conservative default definitions cause considerable insecurity about the loss for a long time after the default. We present three approaches to account for defaulted counterparts...

Rare and randomly occurring events are important features of the economic world. In continuous time they can easily be modeled by Poisson processes. Analyzing optimal behavior in such a setup requires the appropriate version of the change of variables formula and the Hamilton-Jacobi-Bellman...

Ende der 90er Jahre schien eine intensive Auswahl der Investments kaum notwendig, da fast jede Aktienanlage deutliche Kursgewinne versprach. Nach dem jähen Absturz an den Börsen haben die Anleger einen beträchtlichen Teil ihres Aktienvermögens verloren. Damit rücken wieder verstärkt...

Owners of private companies are often highly underdiversified which exposes them to idiosyncratic risk. We investigate the consequences of underdiversification at the company level. Information on US companies and their owners is obtained from the Survey of Consumer Finances and the Survey of...

This study focuses on the diversification benefits of the most developed equity markets of Central and Eastern Europe (CEE). To evaluate these benefits of diversification we use so-called spanning tests based on a stochastic discount factor approach and estimated by General Methods of Moments...

Owners of private companies often invest a substantial share of their net worth in one company, which exposes them to idiosyncratic risk. For US companies we investigate whether owners require compensation for lack of diversification in the form of higher returns to equity. Exposure to...