John T. Dunlop, 89, secretary of labor during the Ford administration and a leading labor-management expert of the post-World War II period, died Oct. 2 at Boston's Brigham and Women's Hospital of heart and kidney illnesses.

Mr. Dunlop, who quit the Cabinet in January 1976 after President Gerald Ford vetoed a bill that would have expanded picketing rights for construction trade unions, is regarded as a leading scholar of labor economics and a consummate negotiator who pioneered innovative solutions to thorny issues. He headed the Cost of Living Council in 1973 and 1974.

Mr. Dunlop, appointed by Ford in March 1975, resigned after the president vetoed the "common site" picketing bill, which he had earlier promised to sign. The bill would have allowed construction unions to picket an entire building site over a dispute with a single subcontractor. The president's veto followed vocal conservative opposition to the bill, and the veto so angered organized labor leaders that they vowed to have nothing to do with the administration. Mr. Dunlop, who had pushed for the change, said he could no longer conduct effective policy in the department and resigned.

"He was the last surviving member of a small group of people who came of age during World War II . . . who had the respect of both business and labor," said Derek Bok, the former president of Harvard who considered Mr. Dunlop his mentor.

Mr. Dunlop was born in Placerville, Calif., to Presbyterian missionary parents and grew up in the Philippines. He graduated with bachelor's and doctoral degrees from the University of California. He joined the Harvard University faculty in 1938 and worked there until his retirement from teaching in 1985.

During World War II, he served on the War Labor Board. He served on the National Labor Relations Board from 1948 to 1952, the Equal Employment Opportunity Commission from 1964 to 1965 and many other federal and state economic boards and commissions. He chaired the 1995 White House Commission on Future of Worker/Management Relations, known as the Dunlop Commission. A Harvard lecture series on housing is named after him. He was one of a handful of "university professors," one of the most prestigious positions at Harvard.

Most recently, colleagues said, he was working on the changing economics of the apparel industry.

"My personal favorite John Dunlop story is the quip that U.S. labor relations policy in the second half of the 20th century was essentially John Dunlop's Rolodex," said Elaine Bernard, head of Harvard's labor and worklife program. "His calendar today would still look like the calendar of the thoroughly engaged."

Mr. Dunlop's 1958 book "Industrial Relations Systems" set the standard analytic framework for the field, said Thomas Kochan, a Massachusetts Institute of Technology professor who served with him on the Dunlop Commission.

"He had an unparalleled ability to move across the worlds of academic theory, policymaking and mediation," Kochan said. "He had big ideas and translated them into practical results."

Mr. Dunlop helped resolve disputes in construction, railroads, textiles and apparel, agriculture, and state and local government, Kochan said. He crafted a three-way deal for migrant workers who picked tomatoes and cucumbers for small farmers who sold to Campbell Soup Co. This pact so satisfied all three parties that it has been renewed at least four times, colleagues said.

"The more complicated a problem was, the more it engaged him," said David Weil, a Boston University and Harvard labor economist.

Mr. Dunlop studied with John Maynard Keynes at Cambridge University in England, where he roomed with another well-known Harvard economist, John Kenneth Galbraith. Yet a colleague told the Associated Press in 1979 that the bow-tied Dunlop was "more at home with a plumbers' convention than with the Harvard faculty."

AFL-CIO President John Sweeney called him the "preeminent authority on labor issues within the U.S. economy. . . . We admired him for his intellect and unfailing civility. And we loved him for his principles and passion for problem-solving."

Bok said Mr. Dunlop personally trained more labor economists and health economists than any other scholar. He was dean of the Faculty of Arts and Sciences from 1969 to 1973 and chairman of the Economics Department from 1961 to 1966.

"He probably saved this university at a very critical time after the student riots in 1968-69" with "leadership and a cool head," Bok said.

Mr. Dunlop's wife of 65 years, Dorothy W. Dunlop, died last year.

Survivors include two sons, a daughter, six grandchildren and five great-grandchildren.

Staff writer Kirsten Downey contributed to this report.