A MATHEMATICAL MODEL IS DEVELOPED TO STUDY THE PRODUCTION OF DOCTORAL, MASTER'S, AND BACHELOR'S DEGREES AND THEIR FEEDBACK INTO HIGHER EDUCATION. FEEDBACK IS DETERMINED BY A SET OF "BASIC BALANCE EQUATIONS" WHICH STATE THAT THE TOTAL RATE OF FLOW INTO A CATEGORY LESS THE RATE OF OUTFLOW IS EQUAL TO THE RATE OF ACCUMULATION OR GROWTH IN A GIVEN CATEGORY. FACULTY DEGREE MIX RELATIONS AND LEAD-LAG RELATIONS ARE ALSO DETERMINED BY SETS OF EQUATIONS. THE PRODUCTS OF BACHELOR'S, MASTER'S, AND DOCTORAL DEGREES ARE SHOWN TO BE FUNCTIONS OF HIGH SCHOOL GRADUATES WHO CHOSE TO GO ON TO COLLEGE, THE AVAILABILITY OF FACULTY AND PHYSICAL PLANT, COSTS, AND A SET OF INTANGIBLE SOCIETAL AND ECONOMIC FACTORS. THE MODEL IS GENERAL AND CAN BE AGGREGATED OR DEAGGREGATED TO SUIT PARTICULAR PROBLEMS. THIS ARTICLE IS A REPRINT FROM "SCIENCE," VOLUME 153, NUMBER 3731, JULY 1, 1966 AND IS AVAILABLE FROM THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE, 1515 MASSACHUSETTS AVE., N.W., WASHINGTON, D.C. 20005. (HW)