My point is that its not as simple as concluding the US wastes money and is ineffective at teaching. The schools in the US do a lot more than instruction, and work with a different set of students.
We certainly could learn from what works around the world, but comparing raw numbers is simply not helpful.
We can also learn from what works in different states. For instance, Massachusetts, as a state, has PISA scores that are on par with the best in the world.
I just don't see a basis for calling them categorically underfunded.
For example, New York State has the highest spending per student $24,040 and is ranked 14th in this survey[0] while Virginia is ranked fourth and only spends $12,216. Massachusetts spends $17,058 and tops the list.
A honest look at the school system may reveal that some parts of it are underfunded, but it will likely also reveal parts that are overfunded. I suspect a lot of progress can be made by being better stewards of the money they currently have, and therefore suggest starting there. Ultimately any taxes come from the wallets of families supporting the children we are trying to help here, making them poorer needs to show benefit to be justified.
We certainly could learn from what works around the world, but comparing raw numbers is simply not helpful.
We can also learn from what works in different states. For instance, Massachusetts, as a state, has PISA scores that are on par with the best in the world.