Taking a break from a 360 review, I direct your attention to the St. Louis area where the Saint Louis Post-Dispatch had an interesting story with big planning implications.
Essentially, young people are moving out and older people are staying put in the western suburbs. The areas that are experiencing decline are the equivalent of DFW's Plano or Lewisville. There's a lot of relevant points here that will effect planners in a profound way.
The size of the American household has been on a constant decrease. The Census numbers are not complete yet, but there is no reason to believe that trend has reversed itself. For the suburbs, that is bad news if they are built out. If no new housing stock is built, and the average size decreases, then obviously there is a decrease of population, but that really isn't the big negative.
The fact that seniors are one of the biggest expenses in a municipal budget is the big tale. Seniors have a greater dependency for social services, like transportation, medical help and other general assistance. In the past, that hasn't been much of an issue on a large scale because family supports were there and seniors were generally a lower porportion of the overall citizen base. However, that is beginning to be less and less, leading to a greater strain on limited government resources.
This is were I am going to borrow an analogy from a guest speaker that appeared while I was in school. As a planner, he likes to compare housing choices to a fruit cart. In these suburbs represented in the story, and repeated all over the country, the houses are all apples. Now apples are nice at times, but so is a variety. As the children age and move out, they would like a pear. The parents who are left behind, would like to trade their apple for a banana. A young couple, who is currently having a peach, would like to have the apple of the older couple if they got their banana. But sadly, for Fruit Cart City, all they have is apples. So, the kids seek their pear somewhere else, some parents leave and get their banana elsewhere too, while most usually stay with their apple. This cause the other couple to look further out for their apple.
This is part of the reasons central cities have been having a renaissance these past couple of decades. As single-family homes were built by successive generations, some planners and cities finally see the importance of a more balanced housing stock. For example, in downtown Dallas a buyer can purchase a high-rise condo or a townhouse, they could rent a reconverted loft unit in a high- or mid-rise, a more familiar garden-style apartment or a hybrid. All across the city are more choices, not just single family house built in the 70's through '90's. The M Streets or North Oak Cliff offer houses from different time periods even, so you can get a Granny Smith, Red or Golden apple in those areas.
These types of areas will appeal to a broader market and constantly replenish itself, keeping its vibrancy in equilibrium. It will also be a bit more sustainable for the municipality. I already mentioned the increased need for services, but on the other end of the spectrum, the older generation is also tax-adverse. Somebody has to pay for their increased services. Typically that is the younger residents. If there are no younger residents, then what?
Now what hapens to the schools in these aging places? Can they ever recover to their pre-aged place? Some can I am sure, but others wouldn't be able to accomplish that. This is part of the equation for why suburbs are unsustainable. In the sixty plus years the modern suburb has existed, none have revitalized themselves on a large scale. Targeted areas have succeeded, but nothing on a municipal level. The coming two decades will be a trial for the inner ring suburbs.
I think at some point, some area will pioneer something to regenerate themselves, or perhaps changing demographic trends will do it for them, but there is too much land area and population for them all to decline. I think at the end of the day, I believe the cities that revitalize will have made a trip to the farmers market and stocked up on different fruits.