You can’t leave out births and deaths when you examine population trends

The release of the latest census population estimates has produced a number of quick takes that say that cities are declining. The latest is Derek Thompson, writing at The Atlantic and bemoaning the net domestic migration out of the New York metro area, and taking that as a sure sign that the city is hollowing out.

And there’s a factoid that’s true here:  More people who were living in New York City in 2010 are living elsewhere in the US in 2016 than people who were living in the US outside of New York City who live there today.

But “net domestic migration” is only one part of the population change puzzle.

A second, that Thompson acknowledges, is international immigration.  New York still is the first port of entry for more people moving to the United States than any other city. (My grandmother immigrated there a century ago; there’s a good chance several of your relatives did, too). New York’s population growth has always been fueled by foreign immigrants.  And foreign immigration has almost perfectly offset domestic out-migration from the city.  Since 2010, net domestic out-migration was -425,000; and foreign immigration was +400,000, so the net loss due to both forms of migration (foreign and domestic combined) was -25,000 (or about 0.3 percent of New York City’s population over a six-year period.

If that were all to the story, then Thompson might have a point (although a very small one).  But there’s a third piece of the population puzzle that he’s omitted altogether: natural increase, or the difference between births and deaths. Though you might not think so given all the “family hostile” rhetoric in Thompson’s article–”Maybe families want to live in denser areas but are being priced out, moving to the suburbs, and buying larger vehicles rather than a small car that can be parallel-parked on a crowded city block”–New York City’s population skews a lot younger than the US.  The result: it produced a lot more babies than funerals.  In fact, the five boroughs are positively fecund by comparison to the rest of New York State.  Over the past six years, the natural increase in the population in New York (i.e. births minus deaths) was plus 400,000–that’s more than 16 times larger than the difference between net domestic outmigration and foreign in-migration.

Leaving out natural increase really mis-states the effect of net-domestic migration.  Some of the people who migrate out of the city in any year are children under the age of six, i.e. people who weren’t here in 2010.  So Thompson’s math excludes these new born kids from his base year calculation, but then counts them when the leave the city. The key point here is that you can’t make sense of the aggregate impact of migration without also looking at natural increase.

And this dynamic is different for different cities:  In Pittsburgh, the reverse is true.  That city’s population skews much older than the US average, and experiences more deaths than births, with the result that its natural increase is negative. To be sure, some people are moving out of New York, but its not demonstrably because they dislike the place, but because the city is becoming increasingly crowded.

Bottom line:  New York City is growing.  When you account for all of the different components of population change–births, deaths, people moving in and people moving out–the city’s population is up in total by almost 400,000 since 2010, an increase of 4.6 percent.  Here’s a synopsis of county/borough level population data for New York City, compiled from Census estimates by the Empire Center.

Not only that, every borough in New York City is growing. Even the Bronx is growing.

As with so many stories that rely on fragments of migration or population data, the narrative that some people are moving out of cities implicitly assumes that they are choosing to leave because they don’t want to live in cities. In fact, the growth of city population, and the rising price of homes in cities is a sign that more people want to live in cities than we can currently accommodate. Our failure to increase the supply of housing in cities is increasingly becoming the constraint on urban economic growth. You’ll know cities are failing when you see house prices and land values dropping.  That will be a sign that consumers have rejected urban living. But that’s not what’s happening in New York City today.