Harry Magdoff, who fell in love with Marxist thought at 15 and became an influential socialist economist, author, editor and commentator -- and, some said, a Soviet spy -- died on Jan. 1 at his home in Burlington, Vt. He was 92.
His son, Frederick, announced the death.
Mr. Magdoff, in his 1969 book ''The Age of Imperialism: The Economics of U.S. Foreign Policy,'' argued that the United States had an empire in all but name. His contention that American imperial ambitions, not anti-Communism, provoked the Vietnam War struck a responsive chord during that conflict. The book sold more than 100,000 copies and was translated into 15 languages.
For many years, Mr. Magdoff was co-editor of Monthly Review, a socialist journal, with Paul Sweezy, an influential Marxist economist who died in 2004. Together, they wrote many articles, some published in five books of essay collections. Their combined work, to which Mr. Magdoff supplied the more technical economic analyses, added up to a running commentary on what they deemed inherent deficiencies of modern capitalism.
Mr. Magdoff also held several influential positions during the Roosevelt and Truman administrations, in which he developed and put into effect new ways of measuring the productivity of labor. His last federal post was as a top aide to Commerce Secretary Henry A. Wallace, a former vice president who ran for president on a leftist agenda in 1948.
In 1950, Richard M. Nixon, then a congressman, released a report accusing Mr. Magdoff of being part of a spy ring that fed secret economic data to the Soviet Union. Mr. Magdoff declined to answer questions about the allegations at a Senate hearing in 1953 and continued to refuse to talk about the matter in recent years as details emerged from American and Russian archives that some contend added weight to the earlier charges.
In any case, security concerns made it impossible for Mr. Magdoff to remain in government. He worked at a series of private sector jobs, sometimes under assumed names, including salesman for a television production company, insurance broker and stockbroker, a job that he, as a Marxist, particularly loathed.
He gained a measure of financial security by acquiring part ownership in Russell & Russell, a publisher of previously out-of-print scholarly books. He taught part time at the New School for Social Research and elsewhere.
Henry Samuel Magdoff was born on Aug. 21, 1913, in the Bronx, to immigrants from Russia. His father was a housepainter, and one of Mr. Magdoff's earliest memories was the glee with which family and friends greeted the downfall of the czar.
He remembered that as a child he was perplexed, then enraged, when he heard in a playground that Britain ''owned'' India. At 15, he read Marx's ''Contribution to a Critique of Political Economy,'' which aroused his interest in radical economics. He said his most influential youthful experience was witnessing a demonstration of the unemployed in Union Square in Manhattan in 1930.
At City College of New York, he studied engineering, physics and mathematics before being expelled in a dispute with administrators over a leftist student publication. The expulsion came after he helped stage a mock trial of the college president and other officials, none of whom attended.
In 1932, Mr. Magdoff visited Chicago to participate in the founding conventions of the National Students League and the Youth League against War and Fascism. During that trip, he married Beatrice Greizer, known as Beadie, who had been marching on picket lines with her pro-union mother since she was a preschooler.
Mrs. Magdoff died in 2002 after nearly 70 years of marriage. Their son Michael has also died. In addition to his other son, Frederick, of Burlington and Fletcher, Vt., Mr. Magdoff is survived by a grandson.
After finishing his undergraduate degree at New York University, Mr. Magdoff went to Philadelphia to work for the Works Progress Administration, trying to solve interesting economic problems.
''You sat in an office supplied with research materials and were paid every week to sit and think why there was so much unemployment,'' he said in an interview in Monthly Review in 1999. ''Who needed heaven?''
In 2004, Mr. Magdoff wrote about his friendship with Che Guevara, one of his revolutionary heroes. At what proved to be their final meeting before Mr. Guevara's death in 1967, Mr. Magdoff asked what he could do to help Cuba.
''Keep on educating me,'' was the response.
Photo: Harry Magdoff, leftist economist. (Photo by Monthly Review Magazine, 1980's)