College admissions officers operate in a highly competitive environment to attract students who are ready to attend their college. The Common Application was initially developed by colleges to make the application process easier. It worked great for that purpose, but there was an unintended consequence.
Prior to the Common App a student had to work pretty hard to complete applications for three or maybe four colleges. Students took more time to pare down their list, only selecting the schools they really wanted admittance to and schools they thought they could get accepted to.
The Common App changed all of that.
Students now regularly apply to over eight colleges. Some apply to twenty colleges or more!
Colleges have accomplished a common base of information to make their decisions about students, but they have also made it virtually impossible to predict if a student is actually serious about attending.
Admissions departments are in it for the "yield". The need to drive more applications, review more applicants, and send out three to five times more acceptance letters than they have room for, just to ensure they have enough students in the seats come the beginning of the school year.
Every college is in the same game. In the airline business this is known as "overbooking".
This creates a touch environment for admissions teams who are accountable to produce enough students to pay the bills every year.
Early decision is their solution.
Early decision and early action options enable admissions teams to assure their college presidents that a certain percentage of the next year's class is 90% likely to attend.
Students who apply early are much more likely to actually attend upon acceptance, which also means that admissions officers are much more likely to admit them. Even if they are not as qualified as students who apply later on.
All students who apply early have an advantage over their peers. Not only are they demonstrating a sincere interest in the school, they are also demonstrating their organizational abilities in being able to submit their application quickly.
It's true, early decision is not right for everyone. But for some students it can spell the difference between being accepted to college of their choice, or settling for another school they know isn't as good for them.
Stay tuned for more thoughts about this topic, or read some of the following sources explaining more on this issue:
The Case for Early Decision - NY Times Contributor
Which College Admissions Deadline Should You Choose? - US News