Professor Thomas focuses on the relation between accounting information and stock prices. Insights recently developed in this area that suggest fundamental links between accounting numbers and value form the basis of much of his recent teaching and research. He was actively involved in developing the core curriculum and has written cases and other teaching material for the courses he teaches on equity valuation and financial management. Differences between stock prices and fundamental value provide the basis for his examination of various stock trading strategies. Before joining the faculty at the Yale School of Management, he was the Ernst & Young Professor of Accounting and Finance at Columbia Business School.