Urban demographics

A common demographic fact, often overlooked, is that an urban conglomeration cannot sustain its population by birthrate alone. A city's population can grow, be stable or contract, but none of these situations relies on how many residents are making whoopie, as they used to say on "The Newlywed Game."

From the beginning of civilization, the history of cities, metropoli have relied on immigration to swell their ranks and gain importance. The bigger the city, the more influence it has; its market is bigger, its opportunities are more numerous, its strength is geometrically magnified, its reputation is bolstered depending the size of its population. People move to cities. When they move away from a city, the city becomes a town.

Why can't a city reproduce its citizens in sufficient numbers to grow to greatness? Despite the many spiritual and productive rewards a city offers, health isn't among them. Close proximity to so many other people, all of whom harbor diseases (including you, gentle reader) can lower the life expectancy. Also, there are plenty of diversions in a diversions in a city, things that take your mind off some of the baser impulses of simple reproduction. Look at Boston: there is an art museum, a symphony, several theaters, restaurants, Shakespeare on the Common, nightlife, lectures to attend, ball games, all sorts of things that people attend rather than making the beast with two backs in their condo when the workday is done. Sex happens in blue blooded Boston, but probably not as often as it does in Hinton, West Virginia, where there is little else to do.

So West Virginian babies get born and they grow up and they see little opportunity to make a living so they move to a city with a population greater than 2,880. A few make their way to Boston. The same is true of the broods raised in Skunkdrop, Kentucky or Spigot, Iowa. The hinterlands keep a stable population or shrink, drastically in some cases, while cities grow. This was true of Ur, of Alexandria, of Rome, of Bruges, Paris and any other place you can think of up to the present.

This is why when you visit middle America, you'll be struck that most of the people you meet are either very old or children. It is also why longtime urbanites who have lived in a city all their lives complain about the young urban professionals who are moving in and changing the way things were last decade. A city is an organism in flux, always soaking up new blood. If it didn't it would shrivel as Boston had been doing until fairly recently. According to the Census Bureau, Boston's population is a smidge above 600,000. It used to be closer to 800,000. City planners used to plan for a population that passed a million.

Did the city lose population because because people stopped having babies? Human nature being what it is, I doubt that. People moved away and new people didn't move in. It is still going on. Any gain in Boston's population results in a loss for some other, smaller burg somewhere in the world.

I haven't researched Dorchester's census data. I suspect some parts are growing stronger while others are atrophying, like much of Boston overall. The Globe's article on Portland made me think of this. One of the critiques of that city's transportation policy is that it isn't changing residents' behavior so much as it is attracting emigration of citizens attracted by those policies. That is what a city does. Attracting emigration is a city's reason for being.

Yesterday, I promised some whimsy. Not today, I'm afraid. After spending time in New Orleans, I've been contrasting and comparing two very different places in my mind, measuring what each does right and the unintended consequences to which these cultures lead.