I had done a quick calculation of an implied ED boost at Brown vs. EA at Harvard using this year’s admission figures. I took Harvard at their word, see the quote from their website at my post #3 above. This was my calculation:
Harvard: EA% 14.5% (938/6473); adjusted for 200 athletic recruits plus 20 other super hooks, 11.5% (718/6253). RD% 3.4% (1118/30333). The gap between EA% adjusted for special cases and RD% is 8.1%, so let’s take Harvard at their word and attribute the difference to a superior pool.
Brown: EA% 21.9% (695/3170); adjusted for AR and super hooks, 16.1% (475/2950). RD% 6.9% (2027/29554); The gap between the adjusted EA rate and the RD rate is 9.2%. If we now attribute the 8.1% value from Harvard as representing the superior pool factor, the ED% can be seen as 8.0% vs 6.9% for RD on a more apples to apples comparison. There is a difference/advantage, but it is not of the order of magnitude when we simply look at 22% vs 7%, or even 16% vs 7%.
I actually think the 220 number is conservative for H, plus I think it is safe to assume a disproportionate number of EA applicants have some other non-automatic hooks, (e.g. legacy, consistent (not super) donor, URM, faculty children). On top of that is the undoubtedly superior EA pool vs. RD. Even if you don’t take Harvard at their word, the real number is nowhere near 14.5% or even 11.5% vs. 3.4%.
If you are a tippy top student (above median test scores plus top 3% of class), and Harvard is one of your say top 3-5 choices, it doesn’t hurt to go for it. If you get deferred, you are no worse off. If you get accepted, you just have to apply to 4 or less more schools. If you get rejected, time to revisit your essays and LoR’s.
I’d also say if Stanford is one of your top 3-5’s, I might choose to apply SCEA there because they don’t defer so many students, giving you a better read on how competitive your application is.
The only time applying to Harvard SCEA that hurts you (assuming your first semester grades are not going to be a factor and your application is completely buttoned up) is if in fact an ED school is your clear favorite and it would mean foregoing that advantage.