Grant Thornton commissioned two research studies to ask if a company can switch from a Big Four audit firm to another qualified global, national or regional firm -- such as say, Grant Thornton -- without affecting stock price.
Dr. Scott Whisenant, who is affiliated with the University of Houston and the Massachusetts Institute of Technology, found no evidence that companies' stock price declined when they announced a change from a Big Four firm to Grant Thornton. Whisenant studied 244 public companies that changed audit firms from Jan. 1, 2002, to May 23, 2006. The findings were consistent regardless of company size, industry or geography.
According to an investor opinion survey conducted by Harris Interactive, the majority of investors expressing a clear opinion (67 percent) said that a company's decision to change from a Big Four audit firm to another global or national firm outside of the Big Four would not make a difference. The majority (76 percent) also said they believe most companies change audit firms for business reasons such as expectations of specialized expertise, better service, better value or a corporate policy requiring periodic firm rotation and not as the result of a disagreement with its auditors.
"I find no statistically significant evidence of stock price decline in any of the announcement event windows I studied," Whisenant said. "These findings hold regardless of company size, including companies with sales greater than $500 million.”
