Well, in a recent year it was closer to 15% IMO participants when you counted the international students.
To put this in perspective, if you took a handful of math students at random from MIT, you wouldn’t be least bit surprised if one of them was an IMO participant. The same is not true at Michigan.
I didn’t suggest that at all. There is a range of talent at every school, and there is significant overlap between the math majors at Michigan vs that at MIT. For that matter, I expect that the math students in a state flagship Honors College have significant talent overlap with students at MIT.
But re Michigan specifically, it used to be pretty common for math students to apply EA simultaneously to MIT and Michigan (Michigan used to respond before the end of December, making it a great EA option). While admissions for any one person is imprecise, we can expect that MIT got its admissions right in the aggregate, meaning that they picked what they thought were the best students they believed would fit at MIT. And if a student was fortunate enough to be accepted to both Michigan and MIT, the vast majority would choose MIT, leading to a talent separation between the two.
This seems like such a basic concept–that student bodies can overlap and yet be different–that I don’t understand the resistance to accepting this.