What drives banks' geographic expansion? the role of locally non-diversifiable risk

We show that banks that are facing relatively high locally non-diversifiable risks in their home region expand more across states than banks that do not face such risks following branching deregulation in the 1990s and 2000s. These banks with high locally non-diversifiable risks also benefit relatively more from deregulation in terms of higher bank stability. Further, these banks expand more into counties where risks are relatively high and positively correlated with risks in their home region, suggesting that they do not only diversify but also build on their expertise in local risks when they expand into new regions.