A Myth Exploded

Every so often I read the following argument: "We shouldn't upzone popular urban neighborhoods, because if we freeze the status quo in those areas, the people who are priced out willl rebuild our city's devastated neighborhoods."  This argument has a conceptual flaw: most middle-class peoples' choices aren't limited to rich urban areas and poor urban areas, because they can always move to suburbia. 

A recent blog post by Chicago blogger Daniel Kay Hertz makes the point decisively.  He shows that Chicago has been so effective at limiting redevelopment in its affluent lakefront areas that such neighborhoods actually lost population in the late 20th century.  If people priced out of rich urban areas inevitably moved to poorer ones, then Chicago's traditionally poor south and west sides would be growing and gentrifying.  Instead, many such areas have lost more than half their 1950 population.