Megan McArdle ponders income mobility, specifically that middle-class and upper-class people brook no challenge to their children’s current economic strata. The result is that we think of mobility as only going in one direction — up — so higher-income parents “pay lip service to mobility, but they work damn hard to make sure that their kids don’t get exposed to a peer group that might normalize dropping out and working low-wage, dead end jobs, or going on welfare.” She continues,

No matter how deeply ideologically committed you are to public education and income mobility, you will not leave your kid in a high-poverty school where gangs are valorized and college is not–or even in a working class school that will close off the chances for admission to Harvard. You’ll agitate against zoning that would bring poor people in (though of course, not because of the poor people, it’s just that, you know, the character of the town is quiet single family houses and the infrastructure won’t support multi-family plus we don’t really have the social services here and they’d be much better off in Camden, actually.) With other like-minded parents, you’ll take over the school and reshape its priorities to match those of the upper-middle class. Or you’ll move to a different school system, naturally talking about the enrichment programs rather than the more affluent, education-focused peer group you’re buying for your kids.

The one thing you will not say–unless you are isolated in a rural area with exactly one school and no critical mass of similar parents–is, “Oh, well, I guess the best we can hope for is a third-tier state school.” It is no accident that the middle class bits of the New York City school system have managed to hijack the best resources for themselves, in the process building a pretty good public school system which exists cheek-by-jowl with a very lousy one.