Why do private schools have waitlists?

Every school has a set number of open “seats” available to new students each academic year, but not every accepted candidate enrolls. The percentage of admitted candidates that enroll is the school’s “yield.” So if a school has 100 openings and an average yield of 50 percent, it will likely accept 200 students to meet its enrollment. But it’s also possible that a school’s yield may fluctuate, or a student might unenroll later. The waitlist is utilized to fill open seats with qualified applicants in these situations.