Regulation and the Management of Expectations - Rating Agencies Revisited

In the aftermath of the 2008 crisis, scholars have begun to revise their conceptions of how market participants interact. While the traditional “rationalist optic” posits market participants who are able to process decisionrelevant information and thereby transform uncertainty into quantifiable risks, the increasingly popular “sociological optic” stresses the role of uncertainty in expectation formation and social conventions for creating confidence in markets. Applications of the sociological optic to concrete regulatory problems are still limited. By subjecting both optics to the same regulatory problem—the role of credit rating agencies (CRAs) and their ratings in capital markets—this paper provides insights into whether the sociological optic offers advice to tackle concrete regulatory problems and discusses the potential of the sociological optic in complementing the rationalist optic. The empirical application suggests that the sociological optic is not only able to improve our understanding of the role of CRAs and their ratings, but also to provide solutions complementary to those posited by the rationalist optic.

Self-dual continuous processes

The important application of semi-static hedging in financial markets naturally leads to the notion of conditionally quasi self-dual processes which is, for continuous semimartingales, related to conditional symmetry properties of both their ordinary as well as their stochastic logarithms. We provide a structure result for continuous conditionally quasi self-dual processes. Our main result is to give a characterization of continuous Ocone martingales via a strong version of self-duality.

Quasi-Self-Dual Exponential Lévy Processes

The important application of semistatic hedging in financial markets naturally leads to the notion of quasi--self-dual processes. The focus of our study is to give new characterizations of quasi--self-duality. We analyze quasi--self-dual Lévy driven markets which do not admit arbitrage opportunities and derive a set of equivalent conditions for the stochastic logarithm of quasi--self-dual martingale models. Since for nonvanishing order parameter two martingale properties have to be satisfied simultaneously, there is a nontrivial relation between the order and shift parameter representing carrying costs in financial applications. This leads to an equation containing an integral term which has to be inverted in applications. We first discuss several important properties of this equation and, for some well-known Lévy-driven models, we derive a family of closed-form inversion formulae.