The announcement that leading international economist Jeffrey D. Sachs ’76 will leave Harvard for Columbia this summer came as a shock to many of his students and colleagues.

Sachs, who is currently Stone professor of international trade and serves as director of Harvard’s Center for International Development (CID), accepted Columbia’s offer of both a teaching appointment and the post of director of the Earth Institute last Thursday.

“We are extremely pleased that Mr. Sachs’ has decided to join Columbia, and to head-up Columbia’s Earth Institute,” said Roy Brunett, a Columbia spokesperson.

But back home, the news of his departure hit students and faculty hard.

“Jeff’s move is unexpected and since he is irreplacable, it is quite a shock,” said Hariri Professor of International Political Economy Dani Rodrik.

“The Department was disappointed to learn that Professor Sachs is leaving, but we are very happy for him in his new position at Columbia,” said Oliver Hart, chair of the economics department. Hart declined further comment.

Students said they would miss Sachs, and commended him for his approachable teaching style and passion for developmental economics.

“It’s especially unfortunate for the students because there are so few truly interesting and dynamic lecturers in the economic department. Many professors have gained a lot of prestige in their research, but lack certain teaching abilities in the classroom, but Sachs definitely posessed both qualities,” said Rani Yadav ’03, who took Sachs’ popular Core class, Social Analysis 60; “The Wealth and Poverty in the World Economy.”

Sachs’ announcement that he will leave for Columbia comes after nearly three decades at Harvard. He entered as a first-year 29 years ago and received both a master’s and a doctorate degree from Harvard before he began to teach. His contributions stretch far beyond the University’s gates, however.

Sachs is best known as an advisor to governments in the developing world and in the creation of Polish and Russian economic policies.

“I am impressed by the rigor of his academic research and the energy of his lectures, but even more uniquely, he practices his humanitarianism beyond Harvard to actually change the lives of many people for the better,” said Jordan Swason ’02, a former student and colleague of Sachs and presently an undergraduate fellow at the CID.

Sachs is also known for his progressive advocacy of economic policies that work to alleviate poverty. He is currently the special advisor to U.N. Secretary-General Kofi Annan on the U.N.’s Millennium Development Goals, which seeks to halve worldwide poverty by 2015. The U.N.’s proximity to Columbia was a major incentive for Sachs to leave Harvard, he said last week.

“Professor Sachs’ dedication to the cause of world poverty reveals that Harvard is losing one of its greatest hearts,” said Sachs’ student Andrea Flores ’05. “It was only a matter of time before he would receive an offer to pursue his vision in a global way. “

“Professor Sachs is not only an international star, he’s an international force in the fight against poverty and disease. Losing him is a blow to the university and to the department,” said Ben Wikler ’03, president of the Harvard AIDS Coalition, a student group for which Sachs was the faculty advisor.

At Harvard, Sachs helped create CID, which is dedicated to improving economic well-being and health in all parts of the world.