Note. Data from Call Reports Balance Sheets, Correia, Sergio A., Stephan Luck, and Emil Verner. 2026. “Failing Banks,”
Quarterly Journal of Economics. Available at
NY Fed. Dollar amounts are in millions (nominal). Total loan figures for 1970–1975 are estimated from subcategory sums due to reporting changes. “All banks” includes commercial banks, savings banks, and other depository institutions reported in Call Reports. “Commercial only” restricts to national banks (NAT), national member banks (NMB), state member banks (SMB), and national trust companies (NTC).
HHI (Herfindahl-Hirschman Index) measures bank market concentration, following Drechsler, Savov & Schnabl (2017,
QJE). For each geographic unit
c (county or state), HHI
c = Σ
b s2b,c, where
sb,c = Deposits
b,c / Σ
b' Deposits
b',c is the deposit market share of bank
b. HHI ranges from 0 to 1. Higher values indicate greater market concentration (fewer banks hold larger shares of deposits); lower values indicate more competition.