Audit clients' investment opportunity sets (IOS) include firm-specific opportunities that are unique to the client, as well as opportunities generalizable to the client's industry and opportunities even more generically available to all firms. Prior research does not examine the variation in...

A report issued by the U.S. General Accounting Office (GAO) in 2003 identified industry specialization as a key driver of consolidation among audit firms and highlighted the extreme levels of auditor concentration in some industries. Like the GAO, we view auditor concentration as a measure of...