"Rightly or wrongly, most schools believe that legacy preference is vital to their fundraising. They believe if they don't give preference to children of alumni, those alumni won't give as much money," Golden said.
It may not be an unreasonable concern. In a 2007 working paper by the National Bureau of Economic Research, two economists chronicled their study of alumni donations at an unnamed selective university. They found that money given by alumni dropped off dramatically when their children were rejected from the university.
Bill Torrey, the chief development officer at Bowdoin College, has experienced the phenomenon firsthand. In his 19 years at Bowdoin, Torrey said he has heard from more than 100 alumni who said they were cutting off their contributions after the rejection of a child or another relative.
But "in most cases, time heals wounds," he said. If a rejected applicant goes on to another college and does well, Torrey said, alumni often "return to the fold."
Hernandez said that when it comes to alumni cash, the size of donations may pale in importance to the percentage of alumni who give. She noted that the magazine U.S. News & World Report uses the rate of giving among alumni as one of its factors in determining its closely watched annual college rankings.
"If you were trying to decide between five schools, wouldn't you want one where the alums love the school? … They want the class participation rate to look high so it looks like people love the school," Hernandez said. "That, in turn, attracts better applicants."
Such benefits notwithstanding, a handful of schools have ended preferences for legacy applicants. Among them is the California Institute of Technology, better known as Cal Tech. This year, the university reported an acceptance rate of just over 17 percent.
The school, Golden said, still raises "considerable amounts of money."
"It may not be as easy," he said, "but you have to appeal to your alumni on other grounds than just their children's admission."
Torrey, of Bowdoin, said that legacy preferences engender alumni loyalty evinced in more than just dollars. Loyal alumni, he said, recommend the school to others, recruit students and can provide career or graduate school guidance to undergraduates.
College officials, Torrey said, "can't say, 'Please be loyal to the place,'" and then not pay attention when an alumnus' son or daughter applies. He said he would feel uncomfortable if the college didn't devote special attention to legacy candidates.
When it comes to reviewing their applications, Torrey said, "We really do bend over backward."