Totally agree. My guess about the curve was wrong the same way as yours and the authors.
If that data's real then I want to know why it's tied to income and not something like wealth.
One wild theory.. quotas are based to income somehow, and that impressively straight line is because admissions officers are really good at their jobs.
Well, for one (and I'm not saying this is the explanation, just an answer to your question), FAFSA student aid eligibility is based on income, not wealth.
Actually wealth is another factor for FAFSA, it's just so seldom that a family has wealth but not income. Things like college savings accounts are actually factored against FAFSA applicants.
If that data's real then I want to know why it's tied to income and not something like wealth.
One wild theory.. quotas are based to income somehow, and that impressively straight line is because admissions officers are really good at their jobs.