It wouldn't surprise me if appreciable, overarching??positive changes in most big-city school districts??occur??only if and when the demographics of??the??big cities in question naturally shift??(emphasis on the word naturally).??Certainly it would be interesting if someone could observe a??metropolitan "tipping point," after reaching which??a city's??schools get much, much better. Perhaps someone already has? Certainly many people claim that individual schools have race and class "tipping points" (i.e., if a school's enrollment is more than 50 percent low income, for example, that school is statistically likely to be??bad and get worse).
