[acdha]

Looking at per-student is hard, though, since it requires adjusting a number of factors. There are the obvious things - cost of infrastructure, needing to pay more in salaries – but also some less obvious differences like the way the U.S. usually has the school system to pay for services which aren't directly related to education.

One major example is special-needs: a single kid who needs an aid or therapist drives up the average massively but that spending doesn't benefit their classmates at all, and urban districts tend to have more of them for various reasons. (This is also an interesting factor in the charter school debate: few of the accusations about cherry-picking students note that some cities don't give the charters the same extra funding for support services, creating a massive penalty for admitting each student)