The initial banking crisis of the Great Depression has been the subject of debate. Some scholars believe a contagious panic spread among financial institutions. Others argue that suspensions surged because fundamentals, such as losses on loans, drove banks out of business. This paper nests those...

In the United States, antitrust authorities rely heavily on numerical measures of local banking market concentration such as the Herfindahl Hirschmann Index to assess the likely competitive effects of proposed bank mergers and acquisitions. This approach to antitrust enforcement relies on two...