On average, regular applicants tend to be different from their Early Action counterparts, Fitzsimmons said. They are less affluent and have less access to good counseling, he said, and are less committed to attending Harvard over other schools.

“The [regular action applicants] may be in families where there is less sophistication or might be from families who have more concerns about studying far away from home,” he said. “We could still see a decline in applications even though demographics suggest we will get a slight increase.”

Acceptance rates may be affected as well.

With the nation facing threats of possible terrorist attacks and international students having to contend with a more rigorous student visa application process, more students may choose to attend schools closer to home.

“We will have to stay alert through the spring and summer,” he said. “After May, it’s possible we’ll do more business off the wait list than usual.”

Despite the upcoming challenges, the admissions office has found another reason to be happy with this year’s Early Action yield.

Fitzsimmons pointed out that while the admissions office is thrilled to set a new record, it also welcomes a leveling off for Early Action application numbers, which have hovered slightly above 6,000 for the last three years.

“We think that some of the hysteria about applying early might be abating, as far as getting in goes,” he said.

This year will mark the first year when applicants can opt to receive notification of admission over a secure e-mail account on Dec. 14. Traditional letters will also be mailed to all applicants, Fitzsimmons said.

—Staff writer Eugenia V. Levenson can be reached at levenson@fas.harvard.edu.