Professor Greenfield is an expert in constitutional law 和 corporate law, 和 clerked at the Supreme Court for Justice David Souter. He is the author of the books: The Myth of Choice, The Failure of Corporate 法律，和 forthcoming Corporations Are 人 Too (And They Should Act Like It).  Along with being a guest on 美国有线电视新闻网 和 微软全国有线广播电视公司, Greenfield’s writings have appeared in the New York Times, Washington Post, Boston Globe, The Nation, The American Prospect, The Atlantic, 和 legal publications such as the Yale 法律 Journal, Virginia 法律 Review, Harvard 法律 和 Policy Review，和 George Washington 法律 Review. 

Professor Greenfield was the Founder 和 President of the Forum for Academic 和 Institutional Rights (FAIR), named plaintiff in a 2006 Supreme Court case challenging the Pentagon’s anti-gay policies; he was instrumental in developing the theory of the cases brought against Unocal Corporation 和 Hershey Corporations for alleged human rights violations in Burma 和 West Africa; 和 he co-authored an amicus brief in Masterpiece Cakeshop v Colorado Civil Rights Commission.