This thesis consists of four chapters, all of which are related to credit risk and particularly modeling of default risk. The chapters can be read independently, and the intended audience differs somewhat among them. The first chapter is methodical; the intended audience consists of...

Classical asset pricing theory assumes \perfect markets" which means that nancial markets are frictionless. However, in the real world nancial frictions exists. Recently the nancial literature has focused more on these frictions and on how they a ect asset prices. This thesis contributes to the...