If everything goes as scheduled, 1994 could be a bad year for Harvard's junior professors.

A federal law prohibiting a mandatory retirement age is slated to take effect at universities around the country then, and many higher education experts say they fear that one result will be a logjam in hiring at schools such as Harvard.

Although higher education officials like Ernst Benjamin, the general secretary of the American Association of University Presidents, say that "national studies are showing that there won't be a problem," Benjamin concedes that the new law may have an effect at certain schools.

"The universities that are going to have a problem are ones where the compensations in faculty life are so attractive that people don't really want to retire," Benjamin said.

And Harvard, according to Benjamin and other national experts, is exactly the kind of research university with excellent facilities and a large endowment that may suffer the effects of the new law, as faculty members decide to hold on to their lifetime posts as long as possible.

In 1986, when Congress passed the federal law forbidding employers to set a mandatory retirement age, it gave universities a seven-year exemption so that they could readjust their benefit plans and insure that they could maintain a high quality staff.

Although universities around the country are planning to lobby Congress to extend their exemption from the law, national experts and Harvard administrators say they expect the new law will go into effect as originally planned.

If that happens, administrators and faculty members say the University will change its pension and benefit plans for professors. But they are less certain about the law's effects on faculty hiring--some say they are afraid a hiring stoppage could occur, though most are concerned that there may end up being too few, rather than too many, faculty members.

Harvard administrators cite recent surveys showing that most professors will not take advantage of the ban on mandatory retirement, and say that nearly 50 percent of the senior faculty will have left Harvard by the year 2000.

According to a national study conducted by the Teachers Insurance and Annuity Association (TIAA), 80 percent of professors surveyed said they plan to retire before age 70. At Harvard, about 45.6 percent of the faculty will be 70 at the end of the next decade.

And that would leave the University in a major bind, professors and administrators say. Essentially, Harvard would then be forced to launch major recruiting drives for professors at a time when it has become increasingly difficult for the University to attract the top-notch scholars it has always sought.

"I don't really think this [federal ban on retirement] is going to be a major problem. I really think the big problem is going to be lack of people rather than too many people," says Aage B. Sorenson, head of the Sociology Department. "I think this actually is a good thing because there is going to be a lack of academic personnel."

Still, the retirement issue has generated much concern in both faculty and administrative circles. Dean of the Faculty A. Michael Spence created a faculty-administrator committee last year to investigate potential policy changes.

"If we do not have regular retirements, bringing newcomers to our faculty will be extremely difficult. I do not think such a situation is likely," Spence wrote in a report released last spring. "But what does happen depends in large part upon our policies as a Faculty and a University."

The committee has not yet completed a report, but its members say they will discuss everything from the practical issue of redesigning the pension plan to the vaguer concern that older professors holding tenure positions indefinitely may prevent the promotion of younger faculty members.