[bromang]

The effect "could be large". Do you have any data to support this?

Some forms of coaching "add over 100". Do you have data to support this?

Poor black/hispanic kids don't have test prep programs in school. So they are unable to get privately provided test prep or have no incentive to do so, and therefore receive a smaller amount of test prep than other racial groups. Do you have any data to support this?

The effects of a superior school "could be large". Do you have any data to support this?

You also say that you learned a lot from black and hispanic pupils. Would you have learned less from white pupils?

[Steko]

Do you really contest that private schools have better outcomes on the SAT? Or that poor kids have less test prep? Maybe you should do some basic googling on the subject before you start tossing around strident conclusions.

Having a worthwhile discussion requires a basic standard of reasonableness. Some of the perfectly reasonable claims I made could have also benefited from citations, sure. OTOH you've given me at least 5 data points that say you've just decided to be a pedantic troll about this topic. Good luck with that.