Unexpected shortfalls of expected Shortfall: Extreme default profiles and regulatory arbitrage

Abstract

The purpose of this paper is to dispel some common misunderstandings about capital adequacy rules based on Expected Shortfall. We establish that, from a theoretical perspective, Expected Shortfall based regulation can provide a misleading assessment of tail behavior, does not necessarily protect liability holders’ interests much better than Value-at-Risk based regulation, and may also allow for regulatory arbitrage when used as a global solvency measure. We also show that, for a value-maximizing financial institution, the benefits der Show more