My PhD cost me $1.17M (but I'd do it again)
georgeyw.comIf you spent $1.17M on a PhD and you use the word "costed," you should ask for a refund.
PhD is in math, not grammar, and there is a possibility English isn't his first language.
As an aside, I looked at the author's thesis because I thought normally (at least at my school) they include a "Vita" that gives the candidates educational experience. This thesis didn't have that, I'm wondering now if it's not a common thing.
Thanks for pointing that out, I'll adjust the title.
I'm guessing the PhD wasn't in English.
It was written in English.
https://repository.upenn.edu/entities/publication/130b7021-2...
Or maybe English isn't their first language.