Hayes R. Holderness is an associate in the law firm of McDermott Will & Emery LLP and is based in the Firm’s New York office. He focuses his practice on state and local taxation. Hayes has worked as a Tax Policy Fellow for the U.S. Congress Joint Committee on Taxation and served as an editor for the New York University Annual Survey of American Law. Hayes received both his J.D., cum laude, and his LL.M. in Taxation from New York University School of Law, and his B.A. from the University of North Carolina, Chapel Hill. Hayes is admitted to practice in New York.

Arthur R. Rosen is a partner in the global law firm of McDermott Will & Emery LLP. His practice focuses on tax planning and litigation relating to state and local tax matters for corporations, partnerships, and individuals. Formerly the Deputy Counsel of the New York State Department of Taxation and Finance as well as Counsel to the Governor’s Temporary Sales Tax Commission and Tax Counsel to the New York State Senate Tax Committee, Mr. Rosen has held executive tax management positions at Xerox Corporation and AT&T. He has also worked in accounting and law firms in New York City. Mr. Rosen is a Fellow of the American College of Tax Counsel and is listed in the Best Lawyers in America and in the Best Lawyers in New York; he is ranked in Chambers and the Legal 500; he has been named one of the top ten Tax Lawyers by State Tax Notes; and he has been selected as the exclusive winner of the Lexology Client Choice Awards USA & Canada 2014 in the corporate tax category in New York. Mr. Rosen is a past chair of the State and Local Tax Committee of the American Bar Association’s Tax Section and a past chair of the National Association of State Bar Tax Sections. He is a member of the Executive Committee of the New York State Bar Association’s Tax Section, and has served as co-chair of its Committees on New York State Tax Matters, New York City Tax Matters, and State and Local Tax Matters. He also served as President and Chairman of the NYU Tax Society and is an active member of the Institute for Professionals in Taxation, from which he has received the Distinguished Service Award. Mr. Rosen was a member of the steering committee of the NTA Communications and Electronic Commerce Tax Project. He founded and chairs the annual week-long “Introduction to State and Local Taxes” program, as well as the “State and Local Taxation II” program, offered at New York University. Mr. Rosen serves as a member of the New York State Commissioner of Taxation and Finance’s advisory council, the New York City Commissioner of Finance’s advisory council, and the New York City Tax Appeals Tribunal’s advisory council. Mr. Rosen was the founder and editor of the monthly newsletter Inside New York Taxes and the co-editor of the semi-monthly newsletters New York Tax Highlights and New York Tax Cases; he was the original editor-in-chief of CCH’s E-Commerce Tax Alert, and was the monthly tax columnist for the E-Commerce Law Journal. He is chair of Bloomberg BNA’s State and Local Tax Advisory Board, is a member of the Advisory Board of the Journal of State Taxation, and has written scores of articles that have appeared in publications such as the Journal of Taxation, the Journal of State Taxation, the Journal of Bank Taxation, the State and Local Tax Lawyer, Multistate Tax Analyst, Inc. Magazine, the Assessment Digest, the Journal of New York Taxation, and The Tax Executive. Mr. Rosen has spoken hundreds of times throughout the country on state and local tax matters.