Measuring corporate diversity in financial services: a diversity index

Abstract

This paper provides a measure of corporate diversity in financial services. Our index is based on four components: ownership; competitiveness; balance sheet structure/resilience; and geographic spread. The first of these sub-indexes measures ownership diversity based on the Berry index of diversification and the Gini-Simpson index of biodiversity. It captures the extent of diversity in ownership types–for the UK, banks, mutuals, and the government owned National Savings & Investment–where each of these have different objectives, creating diversity in behaviour. Our second sub-index captures the extent of competition, and is based on the inverse of the Hirschmann-Herfindahl index of concentration. Our third sub-index measures diversity in balance sheet structures and resilience across the financial sector. Our final sub-index captures the extent of geographic spread and the regional concentration of financial services. These indicators are combined into a single index–the D-Index–that measures diversity in financial services. The D-Index shows a marked decline in the run-up to the 2007–2009 financial crisis, followed by further falls during 2008 and 2009. Since then, the index has remained more or less flat. We are no closer to creating the conditions–of diversity–to avoid a repeat of the 2007-2009 global financial crisis.