The one distinctive factor in a student’s attendance at a private or charter school is a parent who makes the effort to send him there.
Indeed. And if grandma/mom/aunt doesn’t have the desire to get out of bed and transport the child, then the child his happily stuck where he doesn’t have to do anything. In return he will recieve the best life a welfare check can buy.
The gold standard is to compare those who won the lottery to attend a private/charter school with those who did not.
In **every** study using this comparison the child who won the lottery does significantly better than the child who continues to languish in the government's single-payer K-12 indoctrination camp.