Even the American Association of University Professors (AAUP), which strongly endorsed the lifting of the mandatory retirement age, acknowledges that its absence will prove troublesome to schools like Harvard.

"Harvard is one of those places where faculty tend to stay on, because, in fact, there were conditions that made it attractive to do so--lab space, office space, lower teaching loads," says Iris Molotsky, director of public information for AAUP.

"Nationwide it's not thought to be a serious problem," says Detlev F. Vagts, Bemis professor of international law and a member of AAUP.

"In most places people are happy to retire; it's like putting down their monkey wrenches in a factory. When the age rose to 70, they still retired at 65," Vagts adds.

Other observers and that professors at Harvard and other elite schools are more attached to their work and hence more likely to stay on well past retirement.

"I would have stayed on because even now I'm guessing I carry around two-thirds of a [teaching] load," says the Kennedy School's Dillon Professor of International Affairs Emeritus Raymond Vernon, who is 82 years old. "The main thing I've really been relieved of is my paycheck."

Without mandatory retirement, faculty have no incentives to retire and every reason to stay.

"Simply put, professors at Harvard and elsewhere are now guaranteed a job for life, with no reduction in benefits and prospect for a performance review, ever," former Business School dean John H. McArthur wrote in the October HBS Bulletin. "This is an impossible situation for our school."

Older members staying on would not necessarily be a problem, but many observers agree that a reduced faculty turnover rate would be detrimental to the school's mission.

Arnold Professor of Science William H. Bossert '59, master of Lowell House, says that a faculty composed of older professors suffers from intellectual inertia. Older faculty, he says, have less incentive to break from the traditional molds that have been so successful for them.

"If we don't have some faculty refreshment, we really risk not making progress in very innovative fields of research," Bossert says. "[Older faculty] get stuck in research areas that have been extremely productive for them for years, so it's rare for someone in their seventies and eighties to begin whole new lines of thinking. We find that someone in their thirties and forties does."

Even some emeritus professors who say they would have continued teaching without mandatory retirement acknowledge the problem."

"I feel that the earlier rules are probably justified," says Professor Emeritus Jack Montgomery. "I remember from my days as a grad student that I didn't want professors ready for the glue factory."

Fineberg predicts that without a change in retirement policy; 2.5 people will fill a given faculty slot over the next century--down 1.0 from the last century.

"The short of this is that younger people have fewer opportunities," Fineberg says. "This can't be good, especially in ever-changing and dynamic fields."