Meanwhile many may see your statements as an attempt to hijack the thread and veer off-topic from Ability Grouping Research.
While some may do that, my read on his comments is that Bostonian is merely pointing out that the system is so broken that parents are grouping by ability into neighborhoods to ensure that their progeny are schooled among peers.
Ability grouping within schools is criticized because high-SES children are over-represented in the top track and low-SES children in the bottom one. My point is that if you try to put all the children together to achieve equity, and if the high-ability learn little in the untracked classes, the high-ability children with affluent parents will leave. A static analysis will conclude that ability grouping increases segregation by SES, but ability grouping may lead to less segregation by SES than untracking when you account for the responses of parents.
