I'm not sure you can really avoid any sort of gentrification, even if the same people would stay and no one moved away. Guess it's more about the speed and the actual breadth of the income band, or it's the vanishing middle class, when before your kids would maybe move up one notch or two if they got a good job, now it's either "the amount of money feels rich, but still can't buy a house" or continued descent into low income...