THIS COMPARATIVE ANALYSIS INVESTIGATED MOONLIGHTING, MINIMUM ADEQUATE FAMILY INCOME, TEACHERS' SALARIES AS AGAINST THOSE IN OTHER OCCUPATIONS, AND POTENTIAL EARNING POWER. THE AVERAGE ANNUAL INCOME OF ALL TEACHERS IN THE UNITED STATES DURING 1966-67 WAS $6,820, BELOW THAT OF MOST INDUSTRIAL, TECHNICAL, AND PROFESSIONAL EMPLOYEES. IN THE 50 LARGEST CITIES IT WAS $8,024, WITH SAN FRANCISCO ($10,033), LOS ANGELES ($9,078), AND NEW YORK ($8,900) LEADING THE OTHERS. HOWEVER, A COMPARISON OF THESE SALARIES WITH THE MINIMUM INCOME NEEDED BY FAMILIES SHOWED ONLY A SMALL SURPLUS. THUS, THE HIGH INCIDENCE OF MOONLIGHTING AMONG TEACHERS CAN BE ATTRIBUTED TO A DESIRE FOR FINANCIAL SECURITY AND EARNINGS COMPARABLE TO THOSE WITH THE SAME OR EVEN LESS EDUCATION. STATISTICS FOR BEGINNING TEACHERS AND A DETAILED BREAKDOWN OF THE TEACHER POPULATIONS IN THE VARIOUS SCHOOL SYSTEMS (EXPERIENCE, AVERAGE SALARY, PERCENT AT MAXIUMUM SALARY, SUBSTITUTES) ARE ALSO PROVIDED. THIS PUBLICATION IS ALSO AVAILABLE FROM THE AMERICAN FEDERATION OF TEACHERS, 716 NORTH RUSH STREET, CHICAGO, ILLINOIS 60611, FOR $1.00. (LC)