At various times, he was president and chief executive of the Philadelphia Group, executive director of the nonprofit Institute for the Study of Inquiring Systems, and president of Research for Management within the Hay Group, a global management-consulting firm based in Philadelphia. He left Hay and did private consulting until retiring in his mid-70s.
He wrote numerous publications, including The Meaning and Sources of Marketing Theory, published in 1965 and used as a text in colleges and universities. With Wroe Alderson, he authored Men, Motives, and Markets. The work was published in 1968 by Prentice-Hall as part of a "foundations of marketing" series.
He also wrote many chapters for texts and reference books in the fields of marketing and statistics.
Early in his career, Mr. Halbert taught at Penn and Case Western Reserve University, where the latter's operations research program was just beginning. He guest-lectured at other universities and spoke at business conventions.
Mr. Halbert had a lively sense of humor, his family said, and was proud that a joke he told Isaac Asimov over dinner was included in one of the author's joke books. The family is searching for the book.
Mr. Halbert was a tinkerer who loved all things electronic. In his later years he was an active member of the New Horizons Senior Center in Narberth and participated in a writing group that met there.
He joined the Main Line Unitarian Church in 1965 and volunteered with the youth group.
His marriage to Nancy Sickles ended in divorce. He then married Florence Widowski.
In addition to his wife of 54 years, surviving are daughters Sally Leiderman, Janet Alvarez, and Linda Hart; stepchildren Douglas and Louise Lewis; 10 grandchildren; and many nieces and nephews. A daughter, Ellen Mastros, and a stepson died earlier.
A memorial service will be at 11 a.m. Saturday, July 13, at Main Line Unitarian Church, 816 S. Valley Forge Rd., Devon, Pa. 19333. Mr. Halbert donated his body to science.
Donations may be sent to the church.
Contact Bonnie L. Cook at 610-313-8102 or firstname.lastname@example.org.