The last state I resided in with kids still in school was Iowa. My understanding is that total spending per pupil by school district is very close. I just read a mind numbing number of articles and analyses to try and confirm your view… but I still believe I am correct (at least for Iowa).
There are a lot of small exceptions and ongoing disagreements in Iowa (transportation differences, special needs, the up to $175 per pupil diff), but in the main, I believe the funding is equalized.
If you can show me I am wrong for Iowa, I would love to read the analysis and learn.
