Although Harvard College saw 1.9 percent fewer applications this year, the acceptance rate looks likely to decrease nevertheless. Since the admissions office plans to count on a yes from the vast majority of students accepted through its renewed early action program, Harvard may admit as few as 3 percent of the students waiting to hear their decisions this Thursday.

Overall, Harvard might admit about 5.5 percent of students who applied under early action and regular decision to the Class of 2016—a drop from last year’s record-low 6.2 percent.

If the admission rate does fall this year despite the slightly reduced applicant pool, it will be due to a new calculus in the admissions office centered on predicting the number of students accepted in the early round who will choose to come to Harvard.

Dean of Admissions and Financial Aid William R. Fitzsimmons ’67 said that those who were accepted in December under the early action program will be more likely to matriculate. “In the past, the yield for early admission students has been higher than the yield for people applying regular admissions—in fact, 15 to 20 points higher typically,” Fitzsimmons said.

Last year, 77 percent of students accepted—all regular decision, before the return of the early action program—decided to come to Cambridge. If early admits choose Crimson at the rate Fitzsimmons predicted, then as many as 92 to 97 percent of them might matriculate.

Fitzsimmons said he speculates that early action applicants may have a stronger interest in attending Harvard, thus leading to the higher yield rate for those students.

Bev Taylor, founder of college consulting practice The Ivy Coach, said the students she advises typically attend Harvard if they are admitted early. “When they apply early action to Harvard, yes, they go to Harvard,” she said.

Expecting these eager admits, Fitzsimmons said that his office will be conservative in the number of students it admits this year to avoid overcrowding.

Though Harvard has not yet announced the number of acceptance letters that will go in the mail on Thursday, the College will look to roughly replicate the size of this year’s freshman class—1,661.

Already, 772 acceptance letters for the Class of 2016 went out in December.

From this point, anyone with a pencil and paper can approximate the math going on in the admissions office. To be safe, assume that the admissions office, behaving cautiously, makes room for every student who has been accepted early to attend. That leaves about 900 freshman beds open to regular decision candidates. If the yield for that cycle is high as well—say 80 percent—Harvard can admit just over 1,100 more students on Thursday to count on 900 of them showing up.

In total, that means that about 1,900 acceptance letters will go out this year, plus perhaps more to waitlisted students after the first crop of accepted students make their decisions by May 1. Last year, Harvard initially accepted 2,158.

If the number of admitted students is indeed this small, the overall acceptance rate for the 34,285 students who sought admission this year would be 5.5 percent. But that number, already tiny, belies the even smaller odds that an applicant who is waiting for his decision on Thursday hears good news.

The 772 students who were selected in December were picked from a pool of 4,245, leading to an acceptance rate of 18 percent.

This time, 32,967—all regular applicants plus early candidates deferred to the regular round—are competing for just about 1,100 spots. In the regular cycle, a student’s chance of acceptance would be 3 percent based on these calculations.

That these numbers are so small is due to the renewed early action program. “I really believe that would tax on the overall acceptance rate,” Taylor said of early admissions.

But despite the daunting figures, Don McMillan, president of an educational consulting firm in Boston, predicted that students will keep applying to Harvard in similar numbers.

And that means the acceptance rate will not climb much higher. Michael Goran, director of IvySelect College Consulting, said, “There’s still a finite number of seats in a class and there’s a limitation to how much you can expand.”

—Staff writer Elizabeth S. Auritt can be reached at eauritt@college.harvard.edu.