Many urban cores around the United States are experiencing a renaissance, after many decades of demographic decline. Cities may be growing. But urbanization is waning:
More people moved into nonmetro counties from metro areas than in the other direction over the past two decades, according to analysis of annual county population estimates. Urbanization today is fueled by differential natural increase and higher immigration rates.
Over the last 20 years, the U.S. has become increasingly rural. How can one country become more rural and more urban at the same time? It's the birth rate, stupid.
We continue to confuse population change with net domestic migration. I'll start with someone who should know better. Matthew Yglesias raising a strange concern with a Richard Florida chart of net domestic migration:
One unfortunate limit of this dataset is that by limiting itself to domestic migration, and not scaling for population size it creates a visual images that's a little excessively dominated by the idea of massive population loss in the New York City area.
"That's a little excessively dominated." Gen X much? The data set isn't limited. Matthew Yglesias is limited. The New York City area hemorrhages people. We don't notice because of natural increase and immigration (which is related to natural increase). Thus, the fiction persists: Successful urban economies such New York's draw in more people than they export.
Net domestic outmigration isn't necessarily a bad thing. Population decline isn't a crisis reflecting some sort of place flaw. As far as cities are concerned, exodus is the rule. If not for immigration, many of America's largest cities would be shrinking.
A journalist screwing up the distinction between population change and migration is one thing. A politician making the same mistake is quite another. Detroit Mayor Mike Duggan:
Mike Duggan wants to do what no mayor of Detroit has done in more than half a century: attract more people than the city loses.
"The single standard a mayor should be defined on is whether the population of the city is going up or going down," Mr. Duggan said in an interview at his City Hall office six months after he was sworn in.
If he fails, he says he doesn't expect to run in 2017 and win—marking the boldness of his undertaking, considering the long odds he faces.
Mayor Duggan could fail to "attract more people than the city loses" and watch the population of the city go up. See New York City. Duggan could succeed in attracting more people than the city loses and the population could still go down. See Pittsburgh. A big challenge for the City of Detroit are the residential choices of immigrants moving to the metropolitan area. Analysis from Global Detroit (PDF):
The most obvious feature, aside from the clustering, is the lack of immigrants within the city of Detroit. The majority of Detroit’s census tracts contain less than 2% of Foreign-born residents.
Detroit's municipality hasn't demographically benefited from immigration as New York's municipality has. If domestic migration is a measure of Detroit's woes, then New York City is a failure. An above average birth rate isn't a reason to sing the economic praises of a city, particularly when such demographics are converging. Soon enough, the last metric standing will be immigration. Will the influx of Nigerians be enough to save your city? Probably not because most of them will move to gateway suburbs.