Sorry that I missed that. Here is the question:
>>Are the suburbs being followed by the ghettoes, thanks to gentrification in
the urban cores? That might mean the middle-class is shrinking as more of
them stay where they are socio-economically and the upper parts of the
economy rocket off, leaving them behind, thanks to the shedding of
"high-status" workers. <<
To be honest, I don't know how. The shrinking-middle-class has been around for a while. When I worked as a "consultant" for Santa Clara County Board of Supervisors (aka Silicon Valley) I recall receiving a memo from some state tax number crunchers lamenting that phenomenon. But I do not think that middle class is defined by income or at least not alone. Class identity plays a big role, and that identity tends to persist regardless of income. Ditto for the ghettoes - it's the mentality not just the money. Middle class would have to take a gigantic dip to shatter middle class identity.
As far as urban gentrification is concerned, I thing it is a good thing because it tends to keep high income people in the cities, thus increasing tax base and revitalizing cities. Methinks a great deal of US social ills is related to land use, esp. suburban sprawl.
wojtek