Safety in numbers? Geographic diversification and bank insolvency risk

The Riegle-Neal Interstate Banking and Branching Efficiency Act, passed in September 1994 and effective June 1, 1997, will allow nationally chartered banks to branch across state lines. This act will remove impediments to interstate expansion and permit the consolidation of existing interstate networks ; What will be the impact of this legislation on bank performance and bank safety? Removing impediments to geographic expansion should improve the risk-return tradeoff faced by most banks. However, this paper argues that economic theory does not tell us whether an improvement in the risk-return tradeoff will lead to a reduction in the volatility of bank returns or in the probability of insolvency. ; The authors investigate the role of geographic diversification on bank performance and safety using bank holding company data. The authors find that an increase in the number of branches lowers insolvency risk and increases efficiency for inefficient bank holding companies; an increase in the number of states in which a bank holding company operates increases insolvency risk but has an insignificant effect on efficiency. Branch expansion raises the risk of insolvency for efficient bank holding companies, while an increase in the number of states has an insignfiicant effect on insolvency risk