<p>Some EA applicnats will be the strongest because they will not need a higher SAT score or a higher GPA from senior year to increase their chances. However, there are some very strong RD applicants who did not get into HYPS early (you cannot apply EA to Chicago and early to any of the 4). The concentration of strong applicants is higher early for all schools, but the number of strong applicnats is greater in the RD round (as seen by higher % of the class admitted RD), but the number is somewhat diluted at most colleges. Why EA affects low income applicants, I do not know. ED hurts low income applicants because they cannot compare aid and merit scholarships. EA applicants can compare everything and are not obliged to attend the university. Applying EA should not help your chances because the college commits to you, not you commiting to the college. EA yeilds are up at colleges like UChicago because many applicants who get in EA do not wish to go anywhere else and are done with the application process.</p>