Why Do Banks Hold Capital in Excess of Regulatory Requirements? A Functional Approach

Abstract

This paper provides an explanation for the observation that banks hold on average a capital ratio in excess of regulatory requirements. We use a functional approach to banking based on Diamond and Rajan (2001) to demonstrate that banks can use capital ratios as a strategic tool for renegotiating loans with borrowers. As capital ratios affect the ability of banks to collect loans in a nonmonotonic way, a bank may be forced to exceed capital requirements. Moreover, high capital ratios may also constrain the amount a banker can borrow from investors. Consequently, the size of the banking sector may shrink.

Keywords: Incomplete contracts, minimum capital requirements, bank capital, disintermediation, pro-cyclicality

JEL Classification: G21, G28