Did covenants distort risk signals from bank subordinated debt yields before the financial crisis?

Restrictive covenants on bank debt require a bank to take or refrain from specific actions that affect the riskiness of that debt. Although covenants all but disappeared in the 1990s, they re-emerged after 2004 with an increase in bank risk leading up to the financial crisis. Subordinated debt yields potentially enable better risk monitoring by supervisors, but covenants can shift risk from bondholders to stockholders without reducing overall bank risk. This can distort the risk signal used by market participants to discipline excessive risk taking. Because covenants are endogenous and increase during periods of bank stress, the yield signal is dampened the most precisely when regulators most need accurate risk monitoring.