This article theoretically examines how equity capital cost affects return performance and safety of a bank and how this effect varies across a financial crisis comparing to a normal time when the bank manager’s performance reveals the like of higher equity return and the dislike of higher equity risk. We derive two main results. First, an increase in the bank’s equity capital cost from an increase of the interest rate of the Federal funds results in a reduced loan risk-taking at an increased optimal bank interest margin, implying better bank performance. Second, by ignoring the dislike, we find that the better performance is reinforced during a financial crisis but is reduced during a normal time. Financial crises and the dislike preference as such contribute a relatively low return and the stability of banking activities.

Purpose: This paper aims to develop a barrier cap option model, i.e. a cap option model where default can occur at any time before the maturity date, to evaluate the equity and the default risk of a bank. The model implies the bank as a liquidity provider that one institution carriers out both lending and deposit-taking functions under the same roof. This paper studies the impacts of demand deposits and capital regulation on the optimal bank interest margin, i.e. the spread between the loan rate and the deposit rate. Design/methodology/approach: This paper characterizes the bank’s equity value by a barrier cap option framework. In the model, default can occur at any time before the maturity and loan markets are imperfectly competitive. Findings: This paper has two main results. First, increases in demand deposits reduce the bank’s interest margin and further increase the bank’s default risk. The negative effect on the optimal bank interest margin which ignores the barrier leads to significant overestimation; the positive effect on the default risk which ignores the barrier leads to underestimation. Second, the same pattern of capital regulation as previously applies. Capital regulation as such makes the bank more prone to loan risk-taking, thereby adversely affecting the stability of banking system. Originality/value: This paper reintroduces the knock-out value and bank interest margin determination within a synergy banking function to the cap option model. The results confirm the need to model bank equity as a barrier cap option and demonstrate its usefulness in capital regulation.

A retrenchment in crossborder credit is under way, the product of both market forces and political pressure on international banks to lend at home (Economist, 2009). In addition, banks, particularly the largest, have also dramatically expanded their retail banking operations over the past few years (Hirtle and Stiroh, 2007). Our goal, in this article, is to study the effects of default risk on equity returns through bank interest margin management under a renewed focus on domestic retail banking, a trend often attributed to the stability of banking activities. Specifically, this article explores the determinants of optimal bank interest margins based on an option-based firm-theoretical model with multiple sources of structural breaks due to political pressure. The model demonstrates how capital regulation and political pressure on foreign lending return and risk conditions jointly determine the optimal bank interest margin decision. We show that a more stringent capital requirement is linked with lower equity return, but higher default risk of the bank in the return to domestic retail banking. An increased focus on the political pressure on foreign lending return is linked with higher equity return and default risk of the bank. It is also showed that an increased focus on the political pressure on foreign lending risk decreases the bank's equity return and default risk. We conclude that the return to domestic retail banking may be a relatively stable activity when the political pressure decision impacts only the expected risk of the bank's foreign lending and not the return.