This article in yesterday's Wapo (https://www.washingtonpost.com/politics/trump-who-often-boasts-of-his-wharton-degree-says-he-was-admitted-to-the-hardest-school-to-get-into-the-college-official-who-reviewed-his-application-recalls-it-differently/2019/07/08/0a4eb414-977a-11e9-830a-21b9b36b64ad_story.html?utm_term=.a0ea1abd58bb&wpisrc=nl_most&wpmm=1) claims that in 1966 over half of all Penn applicants were accepted (with an even larger percentage of transfer applicants), and even as recently as 1980 it was over 40%.
IIRC, Cornell's acceptance rate in the 1960s, when yours truly attended, was much lower, and for specific colleges (notably A&S and Engineering), lower still.
Maybe the above-cited article is confusing Penn as a whole with the Wharton School. Again, in the 1960's undergraduate business programs were generally viewed with disdain, and IIRC, Penn was the only Ivy with one.
Do you know more about either subject: Ivy admission standards over time or how undergraduate business programs gained legitimacy at elite institutions?
It's business school. Remedial micro-economics and some pseudo-psychology to help you sleep at night because you're lying to people and stealing their money.
In 1970 it was 34% at Cornell. See: https://cdsun.library.cornell.edu/?a=d&d=CDS19660525.2.51&