Education researchers and academic counselors call it "summer melt," the precarious time when some college-bound students fall through the cracks, at risk of abandoning their higher education plans entirely. Studies show that first-generation college students and those from low-income families are particularly vulnerable.

The college is currently admitting students from its wait list and final numbers won't be known until fall, Staab said. There is also likely to be some "summer melt," as students wait-listed at other colleges or universities get in elsewhere.

At William and Mary, 1,140 of the 2,200 students offered admission have accepted. Another 100 students on the waiting list have since been offered admission and 75 of these have accepted, bringing the freshman class to 1,215. The college estimates an attrition of about 15 students, which officials refer to as "summer melt," before fall, bringing the class right in on target.