As someone who’s not in the US, can someone enlighten me why there’s such a difference in school level in san francisco in the first place? If the schools have a similar budget shouldn’t they be pretty much the same?
Start with a perfectly even distribution of family characteristics between schools. Make a few random swaps. Now some schools have just slightly more academic-success density than others, but this is enough to attract some other successful families.
Run that out for a few cycles, and the differences quickly become extreme and permanent.
Even if SF could attain that even distribution, it’s inherently unstable.
Putting children with similar learning abilities in the same class-room is better for everyone. Placing an advanced child with a challenged one can hold both students back.