@DeepBlue86 when we were there over move-in, I didn’t meet anyone not admitted ED. So my sense at the time was that it was definitely over 50%. What’s interesting is that EA/RD is probably about a 1/3 yield and I’m wondering whether that’s higher than they expected.
To answer your question about comparability: No. @marlowe1’s point about UChicago using ED not just to increase yield but to find the applicants it wants to admit is a valid one. UChicago is clearly not using ED the way that other schools are.