Census population data show that suburban America is, once again, outgrowing central cities. Even exurban counties, those beyond suburban areas, are gaining population faster than urban ones, for the second year in a row. And the growth that the densest places in the country have enjoyed since the housing bust is actually slowing down.

If there's a back-to-the-city renaissance underway in America, it's hard to find in these broad population trends — which doesn't make much sense if you live in the middle of Washington.

Clearly, something big has been happening in the District. The construction cranes prove as much. Whole neighborhoods have been redeveloped, and urban housing prices have skyrocketed. Demographics have perceptibly shifted in the blocks right around the city's metro stops. The District's population has grown by about 90,000 people in the last decade.

If there is an urban revival anywhere, it's happening here.

The issue is that it's happening almost nowhere else in this very big country. Washington is a national outlier, and even in this region, the shift toward urban living is driven by a smaller sliver of people than we usually acknowledge.

Dousing the enthusiasm of back-to-the-city boosters, economist Jed Kolko writes, "in fact, the U.S. continues to suburbanize."

Last week, the census released new 2015 population estimates for counties and metropolitan areas. The fastest growing big metros in the country right now are less-dense Sun Belt favorites, like Las Vegas, Orlando and Houston. And the fastest growing counties are in the suburbs of Sun Belt metros, outside of cities like Austin, Denver, San Antonio and Atlanta.

Counties aren't an ideal geography to trace living patterns by population density, since the same county can contain both neighborhoods with tightly packed apartments and large-lot single-family homes. But neighborhood-level data confirms this pattern, too.

Kolko, an independent economist and senior fellow at the Terner Center for Housing Innovation at University of California, Berkeley, has divided all the census tracts in the country by population density. Dating back through the 1990, 2000 and 2010 censuses, the share of Americans living in urban census tracts with about 2,200 households per square mile or more has steadily declined. The population in really dense tracts — with at least 10,000 households per square mile — has fallen, too. And this pattern holds in more recent American Community Survey data through 2014.

Where has the population been rising over this same time? In less-dense places that look like the suburbs.

The fact that America is becoming more suburban doesn't simply mean that people are moving out of central cities into bedroom communities nearby. The overall growth of Sun Belt metros is pushing this trend, too. The densest neighborhoods inside Charlotte, for example, are still less dense than some New Jersey suburbs. That means the long-term migration of people out of the Northeast and Midwest to more sprawling cities in the South and West has helped drive the "suburbanization" trend, too.

But back to Washington. There are 51 metro areas in the country with at least 1 million people. In the overwhelming majority of them, the share of people living in urban neighborhoods has declined since 2000. There are just nine exceptions, metros that are urbanizing — and Washington is one of them, alongside Portland, Seattle and San Jose.

But even in these places, the people partaking in that trend come from a relatively small demographic: They're rich, young, childless, educated and white, according to Kolko. On the whole, as he puts it, people aren't urbanizing in America — wealth is.

This fact is particularly remarkable: "Although the share of the total population living in higher-density urban neighborhoods fell by 5% between 2000 and 2014," Kolko writes, "the share of total national household income received by households in higher-density urban neighborhoods rose by 6%."

This is the story that looks familiar on the ground in the District. Tens of thousands of new residents have moved in, but they include relatively few Baby Boomers and children. Young adults are moving into the city, but they don't represent all millennials. Highly educated people are moving in, but the lower skilled and poor are not.

Where people live isn't necessarily the same as where they want to live, so it's not accurate either to suggest that all these Baby Boomers, minorities and lower-income families would rather live in the suburbs. They may live there because it's where they can afford housing, or because their jobs have relocated there, or because federal policy incentivizes homeownership in the suburbs.

So all these national trends don't entirely debunk the idea that more people would choose city living today than a generation ago if they could. But they highlight that what's happening in the District isn't the same as what's happening across the country.

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