Douglas A. Kahn, the Paul G. Kauper Professor Emeritus of Law, taught courses that included Tax Planning for Business Transactions, Taxation of Individual Income, Corporate Taxation, Partnership Tax, and Legal Process.

He coauthored two casebooks, one on corporate taxation and one on taxation of transfers of wealth, as well as several textbooks on those subjects and on individual income taxation. A coauthored book, Federal Income Tax, was published in 2011, and another coauthored book, Principles of Corporate Taxation, was published in 2010. His recent articles have included "Tax Consequences When a New Employer Bears the Cost of the Employee's Terminating a Prior Employment Relationship" (coauthored), published in the Florida Tax Review; "Prevention of Double Deductions of a Single Loss: Solutions in Search of a Problem" (coauthored), published in the Virginia Tax Review; "The Taxation of a Gift or Inheritance from an Employer," published in The Tax Lawyer; and "A Proposed Replacement of the Tax Expenditure Concept and a Different Perspective on Accelerated Depreciation," published in the Florida State University Law Review. Prior to beginning his academic career, Professor Kahn practiced in Washington, D.C., and served as a trial attorney with both the civil and tax divisions of the U.S. Department of Justice. He joined the Law School faculty in 1964.