With all the attention focused on the average CEO in the United States earning 262 times the pay of the average worker and with stock option fiddles now in the news, accounting professor J Edward Ketz asks the obvious question: How valuable are CEOs?

"Some managers are indeed very good and provide great value to their corporations. I submit, however, that very few corporate executives deliver a billion dollars worth of incremental value. Perhaps it is time for society to review the outrageous salaries of today's business executives. Clearly, it is time for investors and managers of pension managers to ask whether there is value added to the corporation from these wealth transfers."

So how much is too much? And is there an appropriate level?