Concentration indicators: assessing the gap between aggregate and detailed data

Banks and other financial intermediaries tend to specialize in market segments where they exercise a competitive advantage. Whereas specialization facilitates banks to benefit from market conditions or their expertise, specialization may be accompanied by concentration of resources in counterparties, regions, industry sectors, or business products, compromising banks’ diversification of their sources of business or income. This lack of diversification increases a bank’s exposure to losses arising from the concentrated portfolio. Therefore, Concentration could work as a magnifying mechanism of financial shocks which may lead an institution to insolvency In fact, the Basel Committee on Banking Supervision (2006) affirms that “concentration is arguably the most important cause of large losses on banks’ portfolios”. The BCBS exhorts financial authorities to supervise and measure the risks of the portfolios of their financial institutions, including concentration risk.