The largest department at Harvard will get a bit larger next year, when two professors will join the economics department as tenured Faculty.

Michael R. Kremer '85, professor of economics at MIT, and Kenneth S. Rogoff, professor of economics and international affairs at Princeton University, both accepted tenure offers recently.

"Both of these economists are simply first-rate and are well-known in the profession," said Jeffrey G. Williamson, chair of Harvard's economics department.

The two tenures mark the first appointments in the department since the internal promotion of Edward L. Glaeser to professor of economics last spring.

Kremer's Feb. 3 tenure acceptance means he will return to Harvard after a seven-year absence. He received both his bachelor's degree in social studies and his Ph.D. in economics from Harvard.

"I'm excited about joining the Harvard economics department, with its outstanding faculty and students," Kremer said. "I also look forward to interacting with scholars in other disciplines, such as political science."

Immediately after his graduation from Harvard in 1985, Kremer and a group of fellow students founded WorldTeach. Based at Harvard, WorldTeach is a private, non-profit organization that sends volunteers to teach in developing countries.

Kremer said he founded WorldTeach to "find perspective on his undergraduate studies."

His current research focuses on the economics of education and research and development.

Kremer was a 1997 recipient of the MacArthur genius fellowship.

Rogoff joins the Harvard Faculty after seven years as a tenured professor at Princeton.

Last semester, Rogoff was a visiting professor at the London School of Economics. He was a 1998 John Simon Guggenheim Fellow.

"I am thrilled to have the opportunity to teach at Harvard," Rogoff said. "I have always had the impression that it is an incredibly exciting place to be for both students and faculty."

Benjamin Bernake, chair of Princeton's economics department, said his colleagues would miss Rogoff.

"He was an effective teacher at Princeton and particularly skilled at working with doctoral students," Bernake said. "Of course we are extremely sorry to lose Ken, both as a colleague and as a friend."