Will Basel II Lead to a Specialization of Unsophisticated Banks on High-Risk Borrowers?*

Abstract

The stability of the banking sector is an essential precondition for a well-functioning economy. Enhancing this stability was one of the main motivations for the elaboration of the new capital adequacy framework, Basel II. The present paper examines the impact of Basel II on risk allocation in the banking sector and its implications for bank capital adequacy. Basel II introduces a two-layer framework for the calculation of the capital requirement for credit risk: (i) a very risk-sensitive internal ratings-based (IRB) approach that will be used by large sophisticated banks and (ii) a standardized approach, much less risk sensitive, which will be used by smaller, less sophisticated banks. We show that because the two bank types compete in the loan market, Basel II may induce sophisticated banks to specialize on low-risk borrowers and unsophisticated banks to specialize on high-risk borrowers. As a consequence, we may face a trade-off between the capital adequacy of the two types of banks, with an ambiguous net effect on financial stability: the risk sensitivity of the IRB approach improves the capital adequacy of sophisticated banks, but it deteriorates the capital adequacy of unsophisticated banks, as their increased risk taking is not appropriately reflected by the standardized capital requirement.