Top executives are most productive, a study says.

That was the finding of a survey was done by an independent research firm for Accountemps, a temporary personnel service. Vice presidents and personnel directors of 100 of the nation’s 1,000 largest corporations said top executives are more productive than office workers, factory workers or professionals such as lawyers and accountants. Accountemps raised the possibility that the executives might have been biased on their own behalf. For the record, the executives ranked executives 8.3 on a productivity scale of 1 to 10, followed by professionals at 7.8 and office and factory workers, both at 6.4.