The direction of causation may be wrong here, because economists of education, sociologists, and other persons familiar with the data are well aware that young people from well-off families are much more likely to begin higher education and much more likely to complete it than poor young people.

Here are some links about the issue. The overall picture in the past decade has been that high-ability, low-income students are at a clear disadvantage in the college admission process compared to low-ability, high-income students. (The links below are in approximate chronological order of publication, from oldest to newest.) Is anything changing recently about this?

http://www.businessweek.com/magazine/content/03_27/b3840045_...

http://www.educause.edu/ir/library/pdf/ffp0621.pdf

http://www.educause.edu/ir/library/pdf/ff0615S.pdf

http://www.tcf.org/Publications/Education/carnrose.pdf

http://www.tcf.org/Publications/Education/kahlenberg-affacti...

http://harvardmagazine.com/2005/05/a-thumb-on-the-scale.html

http://www.theatlantic.com/doc/200511/financial-aid-leveragi...

http://www.thecrimson.com/article.aspx?ref=510012

http://www.equaleducation.org/commentary.asp?opedid=1240

http://www.jkcf.org/assets/files/0000/0084/Achievement_Trap....

http://www.reason.com/news/show/123910.html

http://www.ihep.org/publications/publications-detail.cfm?id=...

http://www.boston.com/news/education/higher/articles/2008/11...

http://www.google.com/hostednews/ap/article/ALeqM5hkBGMsvJKR...