Applications to Harvard College surpassed 20,000 for the first time this year as record numbers of students vie with each other for spots in the class of 2007.

Although unexpectedly large, the increase in applications is in keeping with the historical trend. The number of applicants has increased in 12 of the past 13 years.

The sharp rise is surprising, said Dean of Admissions and Financial Aid William R. Fitzsimmons, because the numbers are beyond what could have been predicted by census data of graduating seniors in the country.

A total of 20,918 students applied this year, an increase of 6.7 percent from last year’s 19,609, according to Director of Admissions Marlyn McGrath Lewis.

Fitzsimmons said that the increase could not be explained away by the rising number of high school graduates nationally, a trend that is projected to continue through 2008.

“It’s an increase in excess of what population increases would have told us,” he said.

McGrath Lewis pointed to several factors that might have contributed to the rise in this year’s applications, including recent changes in Harvard’s early admission policy, stronger financial aid and increased media focus on colleges and universities.

Harvard’s revised admissions policy, which allows consideration of applicants who simultaneously applied to binding Early Decision programs at other schools, may have played a role in this year’s increase McGrath Lewis said.

“We did see a significant increase in the number of applicants who applied to us early,” said McGrath Lewis. “It may have been partially because of the permission we gave people to apply both to an Early Decision program and our Early Action program.”

Bruce Breimer, a college counselor at Collegiate High School in New York City, said he agreed with McGrath Lewis’ analysis of the numbers.

“It was primarily because of the policy change,” said Breimer. “No other school experienced that kind of increase [in early applications]. There’s a direct correlation between that increase and the policy change.”

But Breimer said that Harvard’s decision to consider applicants who might be rendered ineligible upon admission to another school under an Early Decision contract may makes the increase misleadingly large.

He called such students “ghosts in the pool,” referring to the fact that while counted in the number of applicants, they will not be eligible to matriculate at the College.

But Fitzsimmons said that the policy change could not have been the only cause for the increase in total applications.

“It may have added some, but it certainly wouldn’t have accounted for the large increase,” said Fitzsimmons.