In 1998, the department found itself the target of poaching efforts by Columbia University. Nevertheless, the department managed to convince Waggoner Professor of Economics Robert J. Barro to stay at Harvard, even after Barro was reportedly offered a pay package totaling nearly $300,000 from Columbia.

As universities vie to attract top-notch scholars, professors are starting to ask universities to provide packages that can make picking up and moving worthwhile--jobs for a spouse, housing, even help finding schooling for their children.

Knowles says it's reasonable for the university to help professors in this way.

"If someone is to flourish here, we must be sensitive to their needs," Knowles says. "Happy people do good work, and that is especially true for a people-intensive activity like education."

Knowles says that some professors have important obligations to their families and do not want to move.

"The kind of people we invite from outside are likely to be distinguished and well recognized, particularly by their home institutions," Knowles says. "Aiming high, will therefore always be harder. More than half of the turndowns are because of family reasons, some of the other reasons are cultural."

Ties to home institutions can be even stronger for senior professors when they've been showered with honors--made the head of a local center or institute or the editor of an important academic journal.

Chair of the government department Roderick MacFarquhar says this was exactly the case for one professor who recently turned down a tenure offer.