The auditing of financial statements of public companies in the United States is now a regulated industry, and the primary instrument of its regulation is the Public Company Accounting Oversight Board (PCAOB), an entity created by the Sarbanes-Oxley Act of 2002 (SOX). The PCAOB is one element of a politicized regulatory structure and, as a result, future developments in auditing will continue to be difficult to predict. SOX requirements for PCAOB inspections of audit firms substantially increased the possibility that an audit will be subsequently evaluated despite the absence of identified errors in audited financial statements. The SOX requirement for an auditor's opinion on internal controls over financial reporting (ICFR) immediately increased audit costs and continues to generate heated political debate. In addition, certain aspects of audit quality and PCAOB inspections as well as reporting and audit standards have, or will, affect the conduct of audits and the activities of audit firms. The net effect of these changes has been to increase the cost of audits, particularly as a result of increased review, other quality control activities, and the performance of audits of ICFR, where required. In return, the quality of audits in terms of compliance with audit standards has improved significantly. However, the business models of audit firms and the processes for education and certification of accountants have remained substantially unchanged and are major influences on the quality of audits.