Section 404 of the Sarbanes-Oxley Act requires managers to assess, and their auditors to express an opinion on, the effectiveness of internal controls over financial reporting (ICFR). Policymakers expect the ICFR audits to enhance the credibility of firms' financial statements. Prior research...

In June 2007, the PCAOB issued Auditing Standard No. 5 (AS5), superseding Auditing Standard No. 2 (AS2). AS5 significantly changed the rules relating to audits of internal control over financial reporting (ICFR). Policymakers expected AS5 to lead to improvements in audit efficiency and thus a...