Arthur is a member of the National Roster of Arbitrators maintained by the American Arbitration Association, the Section on Real Property and the Subsection on Construction and Development of the State Bar of California; the Real Property Section of the Los Angeles County Bar Association; the Real Property, Probate and Trust Law Section of the American Bar Association; the Dispute Resolution Section of the American Bar Association, The Counselors of Real Estate (CRE), he is the 2007 Chair of the CRE Dispute Resolution Program Committee and a member of the State Bar of California.

He is also on the panel of Arbitrators for the Arbitration Mediation Conciliation Center.