This report is directed toward three major questions: (1) How many moonlighters are there and do they hold their first and second jobs in the same industries and occupations? Economists have studied the trends and relationships of moonlighting and unemployment, hours of work, and wage levels. (2) Who are the moonlighters and why do they moonlight? Psychologists and sociologists have attempted to identify the moonlighters, draw their profile, and describe their motivations. (3) Is moonlighting legal? What degree of control do moonlighters have over competitive moonlighting? Arbitrators have sustained discharges and disciplinary actions by some employers, but upheld employee grievances in other cases. A statistical profile of moonlighters made by the Bureau of Labor Statistics from a survey made in 1965 reports that a total of 3.7 million persons were holding more than one job. These multiple job holders made up 5.2 percent of all employed workers. (CH)