Academics have found that the provision of consulting services to audit clients can have a serious effect on a firm's perceived independence.
And the new SEC rules designed to counter audit independence violations could increase the pressure to provide non-audit services to clients to an increasingly competitive market.
The study (pdf format), by the Stanford Graduate School of Business, showed that forecast earnings were more likely to be exceeded when the auditor was paid more for its consultancy services.
This suggests that earnings management was an important factor for audit firms that earn large consulting fees. And such firms worked at companies that would offer little surprise to the market, given that investors react negatively when the auditor also generates a high non-audit fee from its client.
The study used data collected from over 4,000 proxies filed between February 5, 2001 and June 15, 2001.
It concluded: "We find a significant negative market reaction to proxy statements filed by firms with the least independent auditors. Our evidence also indicates an inverse relation between auditor independence and earnings management.
"Firms with the least independent auditors are more likely to just meet or beat three earnings benchmarks â analysts' expectations, prior year earnings, and zero earnings â and to report large discretionary accruals. Taken together, our results suggest that the provision of non-audit services impairs independence and reduces the quality of earnings."
New SEC rules mean that auditors have to disclose their non-audit fees in reports. This could have an interesting effect, the study warned: "The disclosure of fee data could increase the competitiveness of the audit market by reducing the cost to firms of making price comparisons and negotiating fees.
"In addition, firms may reduce the purchase of non-audit services from their auditor to avoid the appearance of independence problems."
A Lancaster University study in February this year found that larger auditors are less likely to compromise their independence than smaller ones when providing non-audit services to their clients.
And our sister site, AccountingWEB-UK, reports that research by the Institute of Chartered Accountants in England & Wales (ICAEW) showed that, despite the prevalence of traditional standards of audit independence, the principal fear for an audit partner was the loss of the client.