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.
The British term for this is "selection by postcode". From what I read, it does not really lead to perfect SES segregation because even an income above the median may not give you access to the most coveted neighbourhood school or really expensive private alternatives. Ability tracking actually is a better bet if you wish your children to remain in a selective SES environment - statistically, of course, you may always get the outlier high ability kid from a low SES family who is screwed by selection by postcode, or the real dumb high SES kid who profits from it, but that is all anecdotal.
It has been my experience that most parents care about their children's learning only insofar as it provides access to subsequent educational options, ie high achiever or gifted programming, AP classes, college entrance etc., and strive for high SES classrooms not for the academic rigour, but for the social environment - after all, high expectations make for a lot of work and maybe lower grades. It is different for parents of HG+ children who NEED to learn for themselves. And the reason schools don't care about keeping parents like us in the system is that there are simply so few of us that we aren't a critical mass, and disrupt the comfortable system of teaching an average curriculum to the above average and bright but not gifted kids.
