State-Contingent Bank Regulation With Unobserved Action and Unobserved Characteristics
This paper studies bank regulation in the presence of deposit insurance,
where banks have private information on their own ability and their
investment strategy. Banks choose the mean and variance of their portfolio
return. Regulators wish to control banks’ risk choice, even though all
agents are risk neutral and there are no deadweight costs of bank failure,
because high risk adversely affects banks’ ex ante incentives along other
dimensions. Regulatory tools studied are capital requirements and returncontingent
fines. Regulators can seek to separate bank types by offering a
menu of contracts. We use numerical methods to study the properties of
the model with two different bank types. Without fines, capital requirements
only have limited ability to separate bank types. When fines are
added, separation is much easier. Fine schedules and capital requirements
are tailored to bank type. Low quality banks are fined when they produce
high returns in order to control risk-taking behavior. High quality banks
face fines on lower returns to prevent low-type banks from pretending they
are high quality. Combining state-contingent fines with capital regulation
significantly improves upon pure capital regulation.