You are either igonorant or are being dishonest. Most states don't have county-level school districts; and definitely heavily populated ones do not. The district is either rich or poor. Example: mercer island is just across I90 from Seattle in king county, and is one of the richest districts in the nation (since mercer island is rich). The PTA BS is just made up libertarian propaganda (blame the poor people for being poor).
Bussing solves racial disparity within a district, not economic disparity. Course, these often correspond but not always.
Most first world countries fund educations out of the federal budget so it is more equitable; course, the libertarians would call that socialist, but you reap what you sow.
I live in the 10th most populated state and our school districts are at the county level. I know the 24th most populated state also has districts at the county level.
I tried to find statistics based on state, but could not find any data. (A quick google seems to imply that CA, NY, and WA do not do it based on county, but it's hard to say that most states do with only 5 measurements.)
I'm not really sure why your posts are so angry about this topic, but your original assertion was that schools were segregated by wealth, which is obviously not how are schools districts are devised. I understand that your jaded worldview may keep you from accepting this fact.
School districts and towns that they correspond to are often setup explicitly to prevent equitable distribution of resources. It is very human nature to do that in the "got mine get lost" way. property taxes are just s bad way at it (and WA does much better than most states).
Bussing solves racial disparity within a district, not economic disparity. Course, these often correspond but not always.
Most first world countries fund educations out of the federal budget so it is more equitable; course, the libertarians would call that socialist, but you reap what you sow.