To address these objectives, we collected data and analyzed changes in companies’ choice of auditors and in audit fees, computed concentration ratios and other measures of concentration. We developed an econometric model to evaluate how various factors, including the level of market concentration, could explain fees that public companies paid to their auditors. To obtain the views of public companies and accounting firms on audit competition and challenges, we conducted two surveys. First, we surveyed a random sample of 595 of more than 6,000 publicly held companies, some of which had recently changed auditors. 8 Our sample included large public companies.
