Came across this wonderful site today. Waiting for the final decisions, I wanted to know the answer of the following two questions(which might be pretty trivial) :
1. Assume an offer is accepted before April 15th, and a better one comes after April 15. Can you cancel the first and accept the second? Both waitlisted at MIT and Cornell (CAM), and was wondering for the above scenario.
2. What is the average number of students in the waitlist for a program who expects to enroll around 10 people?
I am pretty sure that after April 15th generally you're given two weeks to accept an offer. I think there should be something about that in the April 15th agreement of the U.S. Council of Graduate Schools .
I believe the policy here is that, instead of accepting an offer before the 15th and then cancelling, you should write to the school that you want to accept with, tell them that you're waitlisted at your dream school but would otherwise like to go there, and ask for an extension on the offer.