Audit market concentration and auditor choice in the UK

Abstract

Auditing has an important role in the corporate governance process and is essential in ensuring confidence in the reliability of financial information. It is important to understand the reasons why, given the costs involved, companies change their auditor and choose a particular level of audit assurance. To date, however, only a limited number of studies on auditor choice issues are available, especially in the UK setting. Further, since the downfall of Andersen, the audit market environment has changed significantly, creating a new audit environment to be researched. In light of these recent developments, the objectives of this thesis are to address both concentration and auditor choice issues. It is divided into two separate but interrelated parts. The first part of this thesis provides evidence on audit market concentration in the UK domestic listed company market from 1998 to 2003. The effect of Andersen’s demise on both audit market concentration and audit fees is examined. Using four different size measures (number of audits, audit fees, clients’ total assets and sales), three measures of concentration are calculated. Results show that the UK audit market has now clearly surpassed the tight oligopoly threshold and, despite auditing significantly fewer clients in 2003 than in 1998, the B5/4 managed to increase their fee dominance. In particular, the decline in B5/4 ‘number of clients’ market share was mainly due to their lower share of the newly-listed companies audit market. On the other hand, the slight increase in B5/4 audit fee market share was due to the net impact of leavers concentrating the B5/4 share and joiners diluting it. Voluntary switches to/from the B5/4 had a relatively small impact on B5/4 market share for both measures. Following Andersen’s acquisition by Deloitte & Touche, market levels of audit fee and audit fee rate (audit fee scaled by total assets) have increased markedly, suggesting that more audit effort is being expended as a way to restore confidence about audit quality after the damage caused by Andersen’s alleged misconduct. The acquisition has also contributed to a further increase in ‘audit fee’ market concentration for the 4-firm concentration ratio (CR4) and in the overall Hirschman-Herfindahl Index measure. Although, Deloitte & Touche gained significant market share in terms of both audit fees and number of audits through its acquisition of Andersen, it is PricewaterhouseCoopers that continues to hold the largest market share. Deloitte & Touche retained 93 former Andersen clients (74%), 21 (17%) moved to another B5/4 auditor and 11 (9%) chose a non-B5/4 firm. While former Andersen clients paid higher audit fees, in aggregate, the increase was, perhaps surprisingly, less than for the market as a whole. At the industry level, the B4 firms dominated all sectors, the highest non-B5/4 market share in any industry being just 8%. In 2003, PricewaterhouseCoopers was the leader in 18 out of 34 sectors. The second part of the thesis is divided into two separate studies – auditor change determinants and new auditor selection determinants. These studies use a sample of non financial auditor change companies to test logistic regression models of the determinants of auditor change and new auditor selection. The determinant variables include auditee, auditor and audit characteristics. This part also examines the sensitivity of results to alternative functional forms of the basic model specification. Two definitions of auditor quality – brand name auditor and specialism, are employed. Internal governance issues such as audit committee independence, the duality of chairman/CEO as well as the size/quality of the incumbent auditor were found to be significant determinants of auditor change. Expected future growth in the company, rather than past growth, and audit fee reduction were positively related to audit change probability. Result also suggests that companies changed auditor to improve the perception of auditor independence. By contrast, in the new auditor selection models, corporate governance variables did not appear to be important in determining a different quality (brand-name) auditor. Only the chairman/CEO duality variable was weakly and negatively significant, suggesting that duality is associated with a change to a lower quality auditor. Growing companies are more likely to change to a brand name auditor, consistent with the inability of smaller firms to provide services across an international market. Contrary to agency theory predictions, the results show that a company experiencing increased leverage is less likely to choose a B5/4 auditor, suggesting that B5/4 auditors are being selective in avoiding risky clients. Higher audit fees are paid to new auditors by companies that changed from non-B5/4 to B5/4, reflecting a B5/4 fee premium. However, the higher NAS fee result is contrary to initial expectations. Typically, far fewer variables were significant in the models with audit quality proxied by industry specialism. For the specialism models based on audit fee market share, there is counter-intuitive evidence that a company with a large number of subsidiaries is less likely to move to a specialist auditor from a non-specialist. New specialist auditors were more likely to be preferred when a company experienced an increase in current accruals or a reduction in leverage. In general, the results for these models were less strong and were dependent upon the specialist definition adopted. Finally, the thesis provides evidence that the choice of time variant model (ex-ante, contemporaneous or ex-post) made no significant difference to the overall results. The one exception concerns the ‘growth’ variable, where companies are found to change auditor in anticipation of future growth, rather than as a response to past growth. Further, the use of alternative proxy variables does not greatly influence the regression results. One important exception to this general observation concerns the brand name proxy. When brand name was defined as tier12 (to include Grant Thornton and BDO) the significance level was improved in all models. This suggests that, to some degree, Grant Thornton and BDO are viewed as quality service providers closer in quality to B5/4 than to other smaller audit firms.