One aspect that hasn't been discussed is parental engagement. Because of the nature of compulsory public education, the public schools spend a lot of effort trying to promote parental engagement, because they're dealing with many children who are being neglected at home to varying degrees. In private schools, there's the opposite problem, because not only are wealthier families who select private education prone to tiger mom syndrome, but these parents feel a greater sense of entitlement as paying customers.

On an unrelated note, we have rejected our local privates, because they appear to support their reputations for academic excellence by loading down the children with unacceptably excessive amounts of homework.