In Chicago subrubs school funding is largely based on local property taxes. Expensive neighborhoods have better funded schools. Of course there's also federal f

In Chicago subrubs school funding is largely based on local property taxes. Expensive neighborhoods have better funded schools. Of course there's also federal funding for poor schools so really the worst funded schools are the ones where everyone is lower middle class but the best funded schools are in the richest districts. Of course as you point out parental involvement is more important than funding, but they tend to be correlated and funding still matters.