Mr. Hellerstein has written and practiced extensively in the state tax field, and he has been involved in numerous state tax cases before the United States Supreme Court (including successful arguments on behalf of taxpayers in Hunt-Wesson, Inc. v. Franchise Tax Bd., 528 U.S. 458 (2000), and Allied-Signal, Inc. v. Director, Division of Taxation, 504 U.S. 768 (1992)). He has also been deeply involved in issues relating to state taxation of electronic commerceand, more generally, to cross-border taxation of services: He was a member of the Steering Committee of the National Tax Association's Telecommunications and Electronic Commerce Tax Project; he is currently a consultant to the Organization for Economic Cooperation and Development, serving as the academic advisor to the OECD's Working Party No. 9 on Consumption Taxes; and he has served as a consultant to the United Nations on e-commerce tax issues.
Mr. Hellerstein is the Editor of the State and Local Tax Department of the Journal of Taxation; the Chairman of the Advisory Board of State Tax Notes; a member of the Editorial Advisory Board of the National Tax Journal; and a member of the Board of Advisors of the New York University State and Local Tax Institute. In 2008, Mr. Hellerstein was awarded the National Tax Association's Daniel M. Holland Medal for outstanding lifetime contributions to the study and practice of public finance.