For the first time every in America, there are more individuals classified as 'poor' living in the suburbs than in urban areas.
This, to me, was an inevitable outcome. While I may have a somewhat libertarian bent to me, even I can see the benefits of good development planning. It is true the suburbs offers better schools, and more affordable nice housing - in some areas. The problem is that not all suburbs are created equal. For every nice suburb where soccer moms drive their Lexus SUVs there is a run-down no-growth suburb where a family of 4 struggles to survive.
From a game theory standpoint, cities should have saw this coming and acted. At the individual level, people may (initially) benefit from moving to the suburbs - but over time as class segregation happens and communities are destroyed as more and more like individuals sprawl out, these same people end up getting hurt. In other words, people may not internalize some of the costs of their choices to sprawl out.
People are fatter and less healthy in these slummy suburbs. The poor tend to stick together and richer suburbanites refuse to integrate less afluent suburban areas. Jobs are often scarce in these slummy suburbs so a family finds that it must drive sometimes an hour or more to another slummy suburb (or into the urban center - which is also in decline due to the sprawl) just to get to their job.
I'm reminded of John Edwards oft cited mantra in the 04 election cycle - there are two Americas. ... I don't know about that, but there definately are two different kinds of suburb.