Credit contagion refers to the propagation of economic distress from one firm or sovereign government to another. In this paper we model credit contagion phenomena and study the fluctuation of aggregate credit losses on large portfolios of financial positions. The joint dynamics of firms' credit...

We model aggregate credit losses on large portfolios of financial positions contracted with firms subject to both cyclical default correlation and direct default contagion processes. Cyclical correlation is due to the dependence of firms on common (macro-) economic factors; credit contagion...

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...

[Schlussbetrachtung] Die bisher in den Steuerwissenschaften publizierte Spenden-Literatur verzichtete sowohl auf eine Modellierung der Steuerwirkungen als auch auf die Berücksichtigung umsatzsteuerlicher Konsequenzen. Der vorliegende Beitrag schließt diese Lücke, indem er einer detaillierten...

Die öffentliche Kritik, die 2010 der Senkung des Umsatzsteuer-Tarifs für Hotelübernachtungen von 19% auf 7% folgte, war insoweit überraschend, als der traditionellen Inzidenz-Hypothese zufolge Tarifsenkungen der Umsatzsteuer durch Preissenkungen Konsumenten zugutekommen. Sie wäre berechtigt...

The paper provides a comprehensive overview of modeling and pricing cyber insurance and includes clear and easily understandable explanations of the underlying mathematical concepts. We distinguish three main types of cyber risks: idiosyncratic, systematic, and systemic cyber risks. While for...

In a complete financial market every contingent claim can be hedged perfectly. In an incomplete market it is possible to stay on the safe side by superhedging. But such strategies may require a large amount of initial capital. Here we study the question what an investor can do who is unwilling...

Motivated by the Kyle-Back model of 'insider trading', we consider certain classes of linear transformations of two independent Brownian motions and study their canonical decomposition as semimartingales in their own filtration. In particular we characterize those transformations which generate...

An investor faced with a contingent claim may eliminate risk by (super-)hedging in a financial market. As this is often quite expensive, we study partial hedges, which require less capital and reduce the risk. In a previous paper we determined quantile hedges which succeed with maximal...

We show the existence, for any k E N, of processes which have the same k-marginals as Brownian motion, although they are not Brownian motions. For k = 4, this proves a conjecture of Stoyanov. The law P' of such a weak Brownian motion of order k can be constructed to be equivalent to Wiener...