Christian Koziol Books

Correlated defaults and systemic risk are clearly priced in credit portfolio securities such as CDOs or index CDSs. In this paper we study an extensive CDX data set for evidence whether correlated defaults are also present in the underlying CDS market. We develop a cash flow based top-down approach for modeling CDSs from which we can derive the following major contributions: (I) Correlated defaults did not matter for CDS prices prior to the financial crisis in 2008. During and after the crisis, however, their importance has increased strongly. (II) In line with a plausible default order, we observe that correlated defaults primarily impact the CDS prices of firms with an overall low CDS level. (III) Idiosyncratic risk factors for each single CDS play a major (minor) role when the CDS premia are high (low).

The large volume of literature on convertible bonds addresses two basic complexes of problems: • Why and under which conditions do firms issue convertible bonds? • What is the fair value of a convertible bond? Christian Koziol's dissertation deals with the second problem. His dissertation differs from the predominant part of the literature in two aspects. First, he explicitly considers the strategic character of the conversion decision, as the timing and the volume of con version affect the wealth of the stockholders and the remaining convertible bond holders. Second, he deals with a more general capital structure, where the firm has subordinated debt outstanding in addition to convertible bonds and stocks. Within this setting, he characterizes and analyzes the optimal conversion strategy and the endogenous prices of convertible bonds, stocks, and the additional debt for three cases: all convertible bonds are held by a monopolist, the convertible bond holders act competitively, and the compet itive bond holders are constrained to convert their bonds in one block. The third variant is typical for the option-theoretic valuation of convertible bonds that uses the typical high contact condition for American options.