Reihan Salam writes,

To understand why Mike Bloomberg’s latest round of proposed school reforms is so bloody brilliant, read Lisa Snell on the weighted student formula. The New York Sun points out that WSF bears a faint resemblance to a voucher program, a fact that has vexed left-leaning activists in New York (shockingly enough). And yet WSF is a form of public school choice that unambiguously disempowers the rich and powerful (which is to say, in New York, the loud, obnoxious, and politically active) while strengthening the hand of poor parents.

The Snell piece says,

School closure is another prominent feature of the weighted student formula model. In Edmonton, if a school declines to the point that it can’t cover its expenses with the per student money, the principal is removed and the remaining teachers and facilities are assigned to a strong principal—or the school is closed altogether, and the staff is moved to other, more successful schools. The San Francisco school district closed five schools in 2005 because of under-enrollment and is considering closing or consolidating 19 other schools.

I think that a good indicator of how closely a weighted-student funding formula comes to approximating a real market is whether schools are indeed closed. It’s not so much that you get rid of the worst schools. It’s that the “prospect of hanging” focuses the mind of all of the school officials.