Map of Phoenix and surrounding suburbs.  The Phoenix metro, with 3.3 million people, has 32 incorporated municipalities.  Chicagoland, about three times larger, has 285 incorporated municipalities.

Several years ago I had my one and only (so far) opportunity to visit Phoenix.  Around the same time I visited Las Vegas for the first time.  Both cities are well known among urbanists as being perhaps the leading poster children for suburban sprawl, and the truth is I saw nothing there that would dissuade me of that notion.  Not trying to be judgmental at all, but both cities seemed to have miles and miles of endless subdivisions sprinkled with shopping centers, indistinguishable from one another.  The styles change slightly but the overall pattern is unrelenting.  OK, I guess that is a little judgmental; it's not my preference, but I understand it is the preferred development pattern for perhaps the majority of people in this country.

But that was not the thing that struck me most while I was there.  Both cities are surrounded by gigantic suburbs, many nearly equal in size to the presumptive core city.  Phoenix is surrounded by no fewer than eight municipalities with more than 100,000 residents: Chandler (240,000), Gilbert (208,000), Glendale (227,000), Mesa (439,000), Peoria (154,000), Scottsdale (217,000), Surprise (118,000), and Tempe (162,000).  The smaller metro of Las Vegas has two similarly sized suburbs in Henderson (258,000) and North Las Vegas (229,000) but has large unincorporated areas that function like the mega-suburbs -- Paradise, the actual home of the Las Vegas Strip, has about 230,000 residents, and Spring Valley, just to Paradise's west, has 178,000.

Contrast that with suburbs surrounding Rust Belt cities.  The two largest metros in the Midwest, Chicago and Detroit, have maybe a half dozen suburbs with more than 100,000 residents between them, and none with more than 200,000.  In fact, Rust Belt metros are far better known for their local government fragmentation -- scores, if not hundreds, of small, independent suburbs that scarcely register as neighborhood size entities.

There's a lot that I can disagree with about Sun Belt metros, but on the surface this seems to be one thing they got right.  On balance Sun Belt metros more equitably balance the positive externalities (generous property and sales tax revenues, for example) with the negative externalities (concentrated low-income areas and undesirable adjacent land uses like manufacturing sites) that naturally come with a life in a metropolitan area.  The net result?  Sun Belt metros may be less prone to the socio-economic disparities you typically find in Rust Belt metros.  Reducing the number of mini-suburbs may potentially be a cost saver for local government, and put them in a better position to deal with problems that require a cooperative approach to resolve.

Not that that would be easy.  Many mini-suburbs were established with the express intention of exerting control over a small area, in response to the lack of control the former city residents had in cities.  Mini-suburbs weren't interested in dealing with larger traffic concerns, or the impact of their shopping center on another suburb's town center.  In my opinion they were developed so they would not have to take on -- or even think about -- negative externalities.  Whatever.  In many ways, the benefits that would come from lowered costs related to school district consolidations, shared police and fire service, and other services would outweigh the social cost, or loss of prestige with the loss of some communities.

I can dream, can't I?  If I ruled the metro, I'd merge suburbs.