Annual attrition

Definition

The share of students who stop each year, which is the enrollment a school must replace.

Why It Matters

Lessons end for reasons nothing about the school controls: a family moves, a sport takes the afternoon, a teenager quits. A school losing a third of its students a year has to enroll a third again before it grows at all, so the marketing cost is permanent rather than a start-up expense. Ask for enrollments and withdrawals by month across two years, and ask which teachers hold their students, because attrition is usually concentrated in one or two studios.