.
If “elite” means HYPSM type private colleges, I believe it is more common for such colleges to favor non-URM, non-ALDC lower income applicants than penalize them.
For example, Harvard is one of the “elite” colleges with the most public information about their admission process , due to the lawsuit. In the lawsuit documents, it was revealed that admissions that Harvard was "need blind’ in the sense that admission officers truly did not have access to family income information from the FA forms. However, admission officers still did flag applicants as SES “disadvantaged” based on the information that was available to them, including things like parents’ occupations and wealth of neighborhood/HS. Getting this SES “disadavantaged” flag roughly correlated with less than ~median US income – lower income as well as lower-middle income. Students receiving the SES “disadvantaged” flag for less than US ~median income. were given a significant boost in chance of admission – not as strong as traditional ALDC hooks, but significant none the less.
In the Harvard internal report at http://samv91khoyt2i553a2t1s05i-wpengine.netdna-ssl.com/wp-content/uploads/2018/06/Doc-421-112-May-1-2013-Memorandum.pdf , the Dean of Admissions at Harvard asks the Harvard Internal Research department to analyze whether his admission policies really are favoring lower income students. As summarized in the linked report, OIR found that having a less than ~median US income (old report, at the time median was ~$60k) was a associated with a boost of admission on par with the boost given to Hispanic students, but less than ALDC hooks. The report also shows a graph listing chance of admission by SAT score for >$60k applicants vs <$60k applicants. At all SAT scores >610*2, the kids with incomes below the US ~median had a higher admit rate than the kids with incomes above the US ~median. Among less than ~median US income kids who also had a good 1-2 academic rating, their overall overall admit rate was 24% compared to 15% for above US ~median income with the same academic rating.
The Plantiff’s independent regression analysis found an even stronger lower SES benefit since it analyzed the SES “disadvantaged” flag directly, rather than using income reported on FA forms. It found that with full controls, otherwise unhooked kids (baseline sample) who received the SES “disadvantaged flag” had a 4.6x odds ratio boost in their chance of admission.
I’ve seen comments from admission officers at other “elite” private colleges, which suggest that they use a similar system to the one described above, in which admission officers flags who they believe are lower and/or lower-middle SES kids based on indirect information like occupations and gives the lower SES kids a boost in chance of admission. However, many schools probably use a lower income threshold than Harvard and flag kid who are truly low income rather than kids with incomes near the US median.
Also note that Harvard and others also indirectly give a boost to many higher income kids through hooks like legacy, deans/directors special interest list, and Z-list. These hook groups are full of very wealthy kids, and they receive a stronger boost than low income kids. For example, the Harvard freshman survey found that ~half of entering legacies reported an income of >$500k. All of the above analyses found that legacies get a stronger boost in admission than low SES kids. Harvard clearly has other priorities beyond just reducing the SES of the admitted class.