The president of the American Economics Association and a pioneer in the study of why wages and incomes vary, Professor Rosen was born in Chicago. He graduated from Purdue University in 1960 with a Bachelor of Science. He subsequently studied economics at the University of Chicago, where he received his doctorate in 1966. He taught at the University of Rochester for more than a decade before joining the faculty at the University of Chicago in 1977. He was the chairman of the economics department from 1988 to 1994 and served as editor of the Journal of Political Economy from 1986 until his death. Earlier this year, he assumed the presidency of the American Economics Association, one of the highest honors in the profession. A short time after, he was told he had cancer, Professor Becker said. He is survived by his wife, Sharon, of Chicago, and two daughters, Jennifer Lynn Rosen, of Chicago, and Adria Jill Rosen Zurita, of El Cerrito, Calif.