According to this op-ed, the city of Los Angeles is implementing a sweeping, yet almost completely unpublicized, effort to give historic status to tens-of-thousands of homes and properties across the city, without ever telling anyone about it.
Poor neighborhoods tend to be fatter than rich ones, whether they are urban or suburban. However, poor urban areas tend to be thinner than poor suburban areas, and rich urban areas tend to be thinner than rich suburban areas.
Some media commentary suggests that fast-gentrifying cities such as Washington are unable to attract families. In Washington, the reality is more complex; the city's high-income neighborhoods actually gained children over the past decade.