Haig has written and lectured extensively on various litigation topics and is the editor-in-chief of several treatises. He is the principal author of the Corporate Counsel’s Guide, published by the New York State Bar Association as well as numerous articles and book chapters. He has served as a member of the Board of Advisers to Business Laws, Inc.’s Law Department Management Adviser and as a member of the Board of Editors of Matthew Bender & Co., Inc.’s Federal Litigation Guide Reporter.

Haig was the president of the New York County Lawyers’ Association from 1992 to 1994. He was a member of the New York State Bar Association’s Executive Committee from 1991 to 1994. He was the founder and first chair of that Association’s Commercial and Federal Litigation Section and also chaired its Committee on Federal Courts and its Committee on Multi-Disciplinary Practice and the Legal Profession. Haig was the chair of the Committee on the Judiciary of the Association of the Bar of the City of New York from 1989 to 1992 and also chaired that Association’s Council on Judicial Administration from 1996 to 1999. He was the president of the New York Bar Foundation from 2003 to 2006 and continues to serve as a member of its board of directors. Haig is a member of the American Law Institute, a member of the Executive Committee of the National Center for States Courts’ Lawyers Committee, a director of the Atlantic Legal Foundation, a Life Fellow of both the American Bar Foundation and the New York Bar Foundation, and a director of the Committee for Modern Courts. He is also a member of the Policy Committee of the Departmental Disciplinary Committee of the Appellate Division, First Judicial Department, and has served as a member of the House of Delegates of the American Bar Association.

In February 1995, Chief Judge of the State of New York Judith S. Kaye and Chief Administrative Judge E. Leo Milonas established a Commercial Courts Task Force to create and refine the Commercial Division of the Supreme Court of the State of New York. The co-chairs of that task force are Haig and Judge Milonas. Haig has also been active in efforts to create business courts in many other states and countries.

In 1991, Haig became the only New York lawyer to receive the Award for Excellence in Continuing Legal Education from the Association of Continuing Legal Education Administrators. On May 7, 1995, the New York State Bar Association’s Commercial and Federal Litigation Section presented him with the section's first annual Robert L. Haig Award for Distinguished Public Service, named after him and presented by the section each year.