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Thomas J. Brennan

Stanley S. Surrey Professor of Law

Thomas J. Brennan
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Thomas J. Brennan is the Stanley S. Surrey Professor of Law at Harvard Law School. His research uses mathematical tools and financial economic theory to analyze tax law and develop ideas for tax policy reform. His areas of study include the taxation of capital, the taxation of financial instruments, and the analysis of strategic tax planning. He also uses empirical methods to study the effects of tax laws, including the behavior of multinational firms in response to tax holidays and changes in the taxation of overseas earnings.

Professor Brennan’s research work encompasses a variety of additional topics, including: (1) developing mathematical models showing how apparent behavioral anomalies can be a product of evolutionary forces that select optimal results at the species, rather than individual, level; (2) critiquing the Capital Asset Pricing Model (CAPM) by analyzing whether the market portfolio can actually lie on the efficient frontier; (3) analyzing empirically the impact of economic conditions on judicial decision-making; and (4) using economic and financial theory to study laws and regulations designed to limit risk in the financial system.

Professor Brennan received an AB in mathematics from Princeton University, an AM in mathematics from Harvard University, a PhD in mathematics from Harvard University, and a JD from Harvard Law School. He is admitted to the bar of the State of New York and practiced as a tax attorney with Cravath, Swaine & Moore LLP. He also worked as a strategist for the Capital Markets Strategies group at Goldman, Sachs & Co.

His prior academic appointments include Visiting Professor of Law at Columbia Law School, Professor of Law at Northwestern University School of Law, where he also held a courtesy appointment and taught in the Finance Department at the Kellogg School of Management, and Visiting Scholar at the MIT Sloan School of Management, where he was part of the Laboratory for Financial Engineering.