This paper examines the relationships among capital regulation, deposit insurance, and the optimal bank interest margin. In a model where loan losses are the source of uncertainty, changes in capital regulation or deposit insurance premiums have direct effects on the bank's interest margin. An increase in bank capital requirement or in deposit insurance premiums results in a reduced interest margin under nonincreasing risk aversion. Comparative static analysis also explores the relation between asset quality and interest margin. It is shown that a mean-preserving spread of the distribution of loan losses results in a reduced margin.

This study develops a currency option pricing model under stochastic interest rates when interest rate parity holds, and it is assumed that domestic and foreign bond prices have local variances that depend only on time. We demonstrate how existing currency option models are simply derived from one framework. Empirical tests employing transactions option data reveal that a particularly simple form of the stochastic rate model is uniformly more accurate than a constant rate model for all boundaries and maturities tested.