William is an Associate Professor of Accounting at Arizona State University. Dr. Duncan was formerly a Director with Ernst & Young where he guided tax education for the firm. He is the author or co-author of three textbooks and has published a number of articles on a variety of tax topics in publications ranging from Taxes and The CPA Journal to the Journal of the American Taxation Association. He has taught in the AICPA National Tax Education program for over 20 years.