“Greg Mankiw is a great economist with a clear and insightful understanding of the problems and opportunities that the U.S. economy faces at this time,” Laibson said. “I am glad the economy will be in such good hands.”

Mankiw could not be reached for comment last night.

Several of Mankiw’s students were surprised to learn of the appointment, saying that his departure will leave the economics department short an excellent instructor.

Tina J. Matic ’05, who last year was a member of Mankiw’s seminar on the economist’s view of the world, said she was surprised that he would be leaving Harvard.

“I definitely think he deserves it. He’s brilliant,” Matic said. “He’s probably the best teacher I’ve had here.”

Arturo E. Brillembourg ’04, who took Economics 1011b, “Macroeconomic Theory,” in spring of 2000 when it was co-taught by Mankiw, called his former instructor “very capable as a teacher and as a professor.”

Mankiw has supported Bush’s economic policies in the past.

Earlier in the month, he co-signed a letter with dozens of other academics, “enthusiastically” endorsing Bush’s stimulus package.

Mankiw succeeds Hubbard, who helped craft the $695 billion tax-cut plan that the president proposed last month—and who steps down as Bush’s administration attempts to convince Congress to approve the stimulus package.

Over the past several months, Bush has replaced key members of his economic staff.

Former Treasury Secretary Paul H. O’Neill and former economic advisor Lawrence B. Lindsey both resigned in December, while former Securities and Exchange Commission chair Harvey L. Pitt stepped down in November.

—Staff writer Alexander J. Blenkinsopp can be reached at blenkins@fas.harvard.edu.