There are many factors in selectivity beyond acceptance rate, so looking at acceptance rate alone is a misleading way of comparing selectivity.
One key factor is applicant pool and related admission criteria. Alice Lloyd’s acceptance rate has been questioned, so instead I’ll compare University of Pennsylvania and US Naval Academy. Both colleges had a similar acceptance rate of between 8 and 9% in 2018, and both are highly ranked in USNWR. However, this does not mean they are similarly selective. Instead they have completely different applicant pools and admission criteria, making it silly to compare the two. A particular kid might have great chances at Penn and poor at Navy or vice versa.
The same principle applies when comparing two colleges that are both primarily academic colleges. For example, Caltech and Pomona had a similar acceptance rate and are both smaller colleges in CA that are well ranked in USNWR. However, they have completely different applicant pools and different admission criteria. Most would probably say Caltech is more selective due to Caltech’s self selecting applicant pool. However, Caltech is self selecting towards a particular unique subgroup that is generally high stat stem kids, which isn’t Pomona’s main focus. As such, I’d expect many Caltech admits would be rejected at Pomona due to being an awful fit, including the varied areas of study among other things.
A related factor is the varied degrees of selectivity and admit rate within the college and for different groups applying. For example, in 2018 Cornell’s Dyson School had a 3% admit rate – lower than any college on the list above. However, Cornell’s Hotel School had a much higher 21% admit rate. Just looking at the average admit rate has little to do with the relative admit rate selectivity for a particular group of students within that college.
Cornell Dyson’s admit rate was much higher this year than in 2018 because they doubled the class size in 2019, which brings up another key factor. The widely varying class sizes makes in awkward to draw conclusions from varied admit rates. If all the 4-year colleges in the US suddenly admitted a similar number of students, then the lowest admit rate colleges in that year would probably look something like below. The larger number of applicants means that specific subgroups within those schools are likely extremely selective.
Colleges Receiving Most Applications
- UCLA
- UCSD
- USB
- UCI
- UCSB
I could list many more issues. It can be interesting to compare admit rates, but I wouldn’t recommend using the relative admit rates for much more than amusement. There are far more accurate ways to gauge relative selectivity. Along the lines of that amusement, the 13 colleges with lowest admit rate as listed in IPEDS most recent year (2017) are below. 5/13 are HYPSM; 3/13 are music/arts conservatories; 1 is a LAC; and 1 is a military school. One common trait all of these varied groups share is they are especially affordable for near median income families. Most have near $0 expected cost to parents for typical near median income families.
Lowest Admit Rate 4-Year Colleges: IPEDS
- Curtis – 3%
- Harvard/Stanford – 5%
- Colburn/Juliard/Princeton – 6%
- Columbia/MIT/Yale – 7%
- Brown/Caltech/Navy/Pomona – 8%