What are some of the motivations for changes in accounting principles, changes in accounting estimates and accounting errors? What do you think were the major motivations for CEOs, CFOs, Controllers and Accounting personnel committing financial statement fraud in the many recent debacles like Enron, Worldcom, HealthSouth, Global Crossing, Xerox, Tenet Healthcare, Qwest, Fannie Mae, Freddie Mac, Computer Associates, Halliburton and the many others?Do you think there may be different motivations depending upon the accounting level of the person?