Paul Hill & Tricia Maas, via a kind Deb Britt email:

A debate about “backfill”—whether charter high schools should add students to replace those who drop out—has just begun (see here, here, and here). Some argue that successful charter school models should not have to deviate from their focus by admitting children who don’t enter at the beginning of 9th grade. Others believe that a school is inherently inequitable if it closes its doors to any subset of the local population. The current debate is raw and polarized between the extremes that schools should never have to backfill students, or that they be legally required to replace every student they lose.

As usual, the extremes are unrealistic. There is no way to completely relieve charters of any pressure to backfill, because lost enrollment means lost revenue. On the other side, it makes no sense to require schools to fill every vacancy, no matter when it occurs and no matter whether the newly admitted student has any chance to earn enough credits and skills to graduate.