The data in the table do not reflect earnings for self-employed workers, who often are paid very well. Also, both managerial workers and high-level professionals can make considerably more than the industry average. According to a 2002 survey by the Association of Management Consulting Firms, the average total cash compensation (salary plus bonus or profit sharing) for research associates was $47,826; for entry-level consultants, $61,496; for management consultants, $78,932; for senior consultants, $112,716; for junior partners, $168,998; and for senior partners, $254,817.

According to a 2003 survey conducted by Abbot, Langer, and Associates, the median annual cash compensation for junior consultants was $48,248; for consultants, $58,817; for senior consultants, $80,000; for principal consultants, $98,000; and for senior or executive vice presidents (with an ownership interest in the firm), $144,200.

Besides earning a straight salary, many workers receive additional compensation, such as profit sharing, stock ownership, or performance-based bonuses. In some firms, bonuses can constitute one-third of annual pay.

Only about 2 percent of workers in management, scientific, and technical consulting services belong to unions or are covered by union contracts, compared with 15 percent of workers in all industries combined.