The Stanford Review’s blog has an article about the topic here. I found these numbers interesting:
In a recent Stanford Daily article, it was reported that almost 1/5 of the class of 2013 was legacy, which, according to the article, was defined as having a predecessor who had attended Stanford, such as a parent or grandparent (the article claimed to ignore siblings, although the common application, as I recall it, did let one mention them). This percentage (18 percent) was significantly higher than that of Princeton, another selective university cited in the article as having only 12.7 percent legacies.
In the article, all parts of the Stanford admissions community insisted that, although legacy status matters, it was a minor part of getting accepted. This came in stark contrast to the statistic that legacy is worth an additional 160 points on the SAT versus a nonlegacy applicant, according to a study by a Princeton sociologist, Thomas Espenshade.
However, the statistics cited in the article are not enough to confirm or deny the importance of legacy. A more interesting statistic would be to look at the acceptance rate of legacy students versus that of the general population. In 2007, for example, legacy students made up 14 percent of the incoming class at Princeton, but had a nearly four times greater chance of getting in, with an acceptance rate of 39 percent versus 10.2 for the student body in general. Although, once factors such as socioeconomic background and parental education are controlled for, I would expect the power of legacy to be weaker, this astronomical difference, if true at Stanford would certainly give a possibly excessive edge to legacy students.
Espenshade’s (co-authored) book No Longer Separate, Not Yet Equal (read my full review here) contains a lot of data about preferences at elite schools. Legacy admissions are not its focus, but it does have a few more numbers — they are unfortunately not statistically significant, but they can give us a general idea. According to authors’ calculations, after controlling for various demographic and academic factors, legacy applicants are 87 percent more likely than non-legacy applicants to gain admission to a given elite public school, and 23 percent more likely to get into an elite private school.
Presuming those numbers reflect reality, that’s a pretty big, and pretty unfair, boost. I’m not sure it’s one the government can or should prevent at private schools, but the problem is much greater at public universities — which shouldn’t be doling out taxpayer-funded education according to the parents of the applicants.