After a restless and often radically leftist youth, Mr. Director joined the Chicago law faculty in 1946. He became part of a clique known as the "Chicago School" of economists, which included Nobel laureate Milton Friedman, his brother-in-law.
Mr. Director, who published sparingly, was perhaps best known for his influence on his students and colleagues at the University of Chicago Law School, including the jurists Robert H. Bork and Richard A. Posner. He also founded in 1958 the Journal of Law and Economics, which he co-edited with Nobel laureate Ronald H. Coase.