"due largely to the heavy new 8% tax on our endowment returns, a burden for MIT and only a few other peer schools"

I went digging. Turns out that's a 2025 "Big Beautiful Bill" thing, which raised that from 1.4% to 8% but only for colleges where the endowment exceeds $2,000,000 per student. Which meant MIT, Stanford, Princeton, Yale, Harvard.

https://waysandmeans.house.gov/2025/05/14/ways-and-means-vot... boasts that this "Holds woke, elite universities that operate more like major corporations and other tax-exempt entities accountable".