Applying EA to Chicago clearly does not carry the same relative advantage that an early application does at most other schools that have ED or SCEA. But that does not mean that it doesn’t carry any advantage. (Assuming, for purposes of argument, that there is any advantage anywhere to early applications, and that the relatively higher admission rate isn’t entirely due to things like athletic recruits or a stronger pool.)
Chicago, Harvard, and Duke all have about the same class size. Harvard and Duke maybe have 150-200 more slots per class than Chicago, but they’re close. And all three seem to want to admit about half of their classes in the early round. Harvard has SCEA, Duke traditional ED, and Chicago of course open EA.
Harvard got 4,600 early applications last year, >13% of 34,300 total applications. Duke, with its binding commitment requirement, got 3,200 early applications, <10% of 32,500 total applications. Chicago got an astounding 11,100 early applications, over 40% of its total applications.
From that pool, Harvard early-accepted just under 1,000 students, about 22% of the early applicants, and just under half of its total acceptances including RD. Duke early-accepted 800 students, or 25% of the early pool, but less than 23% of its total acceptances. And Chicago early-accepted 1,350 applicants (12%), which represented 59% of all acceptances.
Chicago’s early admission rate was by far the lowest, because it got such a high percentage of its total applications in the early round. But, still, it actually accepted more students early than in the regular round. Having used close to 60% of its total picks from 40% of the pool, it was left to spread the remaining 40% across 60% of the pool (probably more like 80% of the pool, given deferred EA applicants). The early admission rate was more than twice the regular admission rate. The equivalent comparison at Duke would be a little more than three times the regular admission rate, and at Harvard more than six times the regular admission rate. (The difference is actually larger than that due to deferred early applicants, but this suffices to see the differences among the schools.) The advantage is smallest at Chicago, but still pretty significant.
The way Chicago does it isn’t the only way, though. Georgetown – which does not permit EA applicants to apply ED elsewhere, but is not otherwise restrictive – got almost as high a percentage of its applications early as Chicago, 35%. But it gave out only 30% of its total acceptances early, and its early admission rate was apparently a little below its RD admission rate (they were probably close to the same, taking into account deferrals). MIT – with exactly the same EA rules as Chicago – got 37% of its applications early, and gave out 43% of its acceptances early, with an early admission rate that was about 1.5 times its regular admission rate. (Which, by the way, is about what Chicago looked like until the last couple of years when the number of early acceptances relative to total acceptances soared. But, back then, MIT looked like Georgetown does now – no meaningful difference in admission rate.)