So most colleges have relatively higher acceptance rates during early decision compared to regular decision. My question is that is this due to recruited athletes being included in this? Do they count towards early decision acceptance rates?
Recruited athletes definitely court towards a school’s official early application acceptance rate. It’s definitely not the only reason these early application rates are higher, however. Since there are many kinds of early application types (rolling, unrestricted and not binding, selective and not binding, and selective and binding), those can also affect the acceptance rate for a particular school. I believe the conventional wisdom is that those who apply early tend to be: recruited athletes, legacies, and those who identify the particular school as their top choice (whether binding or not). The last category is by far the largest, and are people who are usually very well qualified for the particular school—this allows an admissions office to select their preferred applicants from that qualified, motivated, self-selective pool. This leads to a higher acceptance rate in general.
Recruited athletes do account for many ED acceptances but I don’t think there is a generally accepted percentage, and must probably vary depending on the size of the school and its athletic program.
ED rates are also higher because they are much stronger but smaller pools than in RD. Admissions offices can really cherry pick the best of ED applicants AND get 100% yield.