Lucas received his B.A. in History in 1959 from the University of Chicago. While he was attending University of California, Berkeley as a graduate student in 1959, Lucas left Berkeley due to financial reasons and returned to Chicago in 1960, earning a Ph.D. in Economics in 1964. His dissertation "Substitution between Labor and Capital in U.S. Manufacturing: 1929–1958" was written under the supervision of H. Gregg Lewis and Dale Jorgenson. Lucas studied economics for his Ph.D. on "quasi-Marxist" grounds. He believed that economics was the true driver of history, and so he planned to immerse himself fully in economics and then return to the history department.