Do you have any evidence private schooling is bad? This is the first time I've heard it's worse than public school.
Is this a result of the private schooling or does the socioeconomic status of their parents play a significant role?
I attended both and the people that were rich enough to attend private school but were sent to public school anyway still did very well for themselves, not obviously different from those that attended private school.
I would reference the confirming NAIS studies as well but they've got some self-interest in those results.
the data is very very old (20 years), but they did not find significant differences after adjusting for the schools / students characteristics. Unadjusted scores however do look better for private schools.
https://www.nationsreportcard.gov/dashboards/schools_dashboa...
Private schools outperform in nearly all subjects.