While I agree with the premise that today's ex-urban and far flung suburbs are not sustainable, I think this prediction ignores the basic fact of why people who are poor are concentrated in the city: they can walk (or ride the bus) to basic services such as the corner/grocery store, health clinic or jobs. How exactly would the poor meet these basic needs in today's subdivisions since you have to drive to get anywhere? Especially as gasoline gets more expensive, these outlying neighborhoods would have nothing to offer the poor.

I agree ... the argument is interesting, but there is no way the poor can easily move out to Howard County McMansions, where a car is needed for pretty much everything.

I would say the communities that are likely to become slums before the McMansions of Harford, Howard and Carroll Counties are the older subburbs of Parkville, Glen Burnie, Pikesville, etc... These areas have aging housing stocks, small lots, and are accessible to public transportation.

I often think American Cities will become like European Cities. We will have a wealthy central city, that is ringed by slums with county estates beyond.

Density of the outer areas may increase because those who bought the houses will no longer be able to afford them, so the units will be subdivided into apartments to pay the mortgage--certainly much to the chagrin of the neighborhood association.

Future living patterns may depend on how densely people are willing to live within a single unit in lower density development versus fewer people living in a unit in a densely developed area (possibly with more social disorder) like Baltimore. I suspect the future will be a combination of the two.

Interesting points, folks. Robert, I thought you might like to read this report by UMBC researchers in 2005, "The State of the Inner Suburbs." It points out that "household income is declining; the population is shrinking and aging; and the infrastructure is weakening."

I suspect half of America to be a slum in the next 50 to 100 years as the middle class is systematically destroyed.

The one county that I think is going to be most affected by the changing demographics in the inner subburbs is Montgomery County. Gone are the days when Monty County was filled with upper income government workers. Increasingly, that county is become third world. Both in the sense that many of the residents of that county are increasingly from the third world, but also in the sense that its income stratification will resemble that of the third world in which there will be a small population of the rich elite and a large population of the poor. The upper middle class that made turned Montgomery County into a desireable suburb know for good schools and good government will leave in favor of the Frederick, Carroll and Howard Counties.

I should take a look at the original, but I suspect a strong dash of wishful thinking from the kind of right-thinking people who've never liked suburbs anyway.

That is of course possible! We'll just have to wait and see.