Though Harvard and Princeton reinstated early admission policies this fall for the first time in four years, Yale still received the greatest number of early applicants and posted the lowest acceptance rate among the three schools.

Yale admitted 15.7 percent of its early action applicants for the class of 2016 on Thursday evening — a slight increase from last year’s early acceptance rate of 14.5 percent, Dean of Undergraduate Admissions Jeffrey Brenzel said in a Saturday email. The total number of early applicants to the University declined about 18 percent from last year as Harvard and Princeton again allowed applicants to apply via single-choice early action. But Yale’s program remained the most competitive this admissions cycle, with Harvard accepting 18 percent of its early applicants and Princeton admitting 21 percent.

While Yale’s 2011 early applicant pool was smaller than last year’s, Brenzel said the University received more applicants this fall than it did during fall 2006 — the last time that Yale, Harvard and Princeton all offered early admissions programs.

“In every category of applicant relative to that prior group, we saw increased strength,” Brenzel said. “Once again, we admitted only those students we felt certain we would also admit if they applied in the spring. The students we deferred are strong candidates whose chances of admission in the spring will be similar to those of the regular decision applicants.”

Yale admitted 675 of 4,304 early applicants and denied admission to 1,180 students. The University deferred another 2,394 — or 55.6 percent of applicants — to the regular admissions pool in the spring, roughly the same percentage that was deferred in 2010.

The ethnic and international diversity of the admitted students is roughly comparable to that of Yale’s student body, Brenzel said. Current Yale students are already in contact with the newly admitted prefrosh through online forums, he added, and the admissions office is preparing for its next round of applicants.

Brenzel said the Admissions Office is hoping to have about 1,350 students enroll for fall 2012 and expects to admit another 1,300 to 1,500 applicants in the spring from the regular pool.

Two college admissions experts and three students who were admitted early to Yale said they think the regular admissions pool will now be more competitive, because they know of several qualified students who applied early but were deferred.

Chuck Hughes, president and founder of Road to College, a college admissions consulting service, told the News last month that he thinks Harvard’s, Princeton’s and Yale’s single-choice early action policies will strengthen regular decision applicant pools because more students will be deferred. Students who are deferred from their first choices are also likely to take offers from peer schools more seriously, he added.

Though the University’s early acceptance rate rose this fall, Robbie Flatow, a senior at Regis High School in New York who was admitted to Yale’s class of 2016, said Yale is still considered a highly competitive school among his peers. The latest early acceptance statistics are unlikely to impact the number of students who apply regular decision to Yale and other Ivy League institutions, Flatow said, since they are still regarded as the most prestigious schools in the country.

“Yale’s still considered a hard school to get into among everybody,” he said.

Flatow said he was thrilled to learn he had been admitted early to Yale. Flatow said he is “about 95 percent sure” that he will attend Yale next year, but will consider other acceptances and financial aid packages before making his final decision.

Cornell is the only Ivy League school not to have released its early admissions decisions yet. Brown, Columbia, Dartmouth and the University of Pennsylvania accepted 19 percent, 20.4 percent, 25.8 percent and 25.4 percent of their early applicants respectively, and Stanford admitted 12.8 percent of its early applicants.

Yale will notify students who were deferred early acceptance and those who apply in the regular cycle of their admissions decisions on April 1.