Warburg Professor of Economics emeritus John Kenneth Galbraith is expected to return to Harvard classrooms later this semester after a December heart surgery.

According to administrative assistant Sylvia Baldwin, the famous economist had a valve replacement and seems to be in good condition. The nonagenarian recently fell, which has prolonged his recovery, but all signs point to a successful surgery.

"He is expecting to be fully back in commission in a few weeks," Baldwin said. She said Galbraith plans to "resume his previous calendar of classroom visits and other events at Harvard."

However, Economics Department Chair Jeffrey G. Williamson said it is unclear how active Galbraith will be. As a professor emeritus, Galbraith restricts his teaching to serving as a guest lecturer when invited.

"He's doing it less and less," Williamson said of Galbraith's lecturing, "as all of us will at that age."

Williamson said the economics department does not want to put any pressure on Galbraith.

"It's a gift, whatever we get," Williamson said of the famed economist's services.

Galbraith has enjoyed a long career as an economist, writer, academic and public servant. Born in Canada in 1908, he taught economics at Harvard from 1934 to 1939 and from 1949 and to 1975, except for time he devoted to government service.

An adviser to President John F. Kennedy '40, Galbraith served as U.S. ambassador to India from 1961 to 1963. Galbraith also authored several widely read books, including his popular The Affluent Society, which was first published in 1958.

In this and other books, Galbraith argued for a Keynesian approach to economics and public policy. He has advocated government spending to fight unemployment and poverty.

Galbraith has remained vocal and active in his later years. Last November, he gave a speech sponsored by the College Democrats. Also in November, he lent his support to a Harvard student's petition to remove a U.S. naval base from the Puerto Rican island of Vieques.