Earlier quoted context omitted.
Your suspicion is correct. I've taught at several US universities, and it's an open secret that the administrative takes steps to manipulate numbers in order to secure better rankings. Typical example: a small, prestigious liberal arts college always has smaller class sizes in the fall semester than in the spring semester. Why? Because classes with less than 30 students are ranked higher by US News, but they only tak…
Why is small class size a good thing? Anecdotally, you get better class material and TA staff in larger lectures. Why aren't Universities able to innovate here?
The same is true for selectivity. It doesn't account for education at all, only the difficulty of getting in. But since it doesn't account for the applicant pool, it doesn't account for the difficulty of getting in either. You could use things like SAT scores as a measure of the difficulty of getting in and ditch the acceptance % completely. I work at an R1 that gets hit hard because we admit most applicants because, you know, we exist to educate folks, not to serve as a signalling device.