How Big a Deal Was BofA's $4 Billion Mistake?

Just how effective are Bank of America Corp.'s accounting controls? It would be easy to say "not very" after the company's disclosure last week of a $4 billion error in its calculation of regulatory capital.

The mistake, which went undetected for years, didn't affect Bank of America's earnings or shareholder equity under generally accepted accounting principles. Yet the flub, which was included in the company's stress-test submission to the Federal Reserve, created enough problems that Bank of America had to postpone a planned dividend increase and stock buyback, just days before its annual shareholder meeting.