Reading the tea leaves in the U.S. population census results.

County Population Change: 2000-2010Now that the full scope of information is being released from the latest U.S. population census, many news reports about age demographics tend to focus on the composition of families in urban areaa … the impact of immigration of all stripes … as well as the occasional article about the phenomenon of large family units in “exotic” places like rural Utah and Idaho.

Most of these news reports give the impression that age demographics are getting younger.

Don’t believe it. Instead, we can turn to the U.S. Bureau of Census’ own figures which tell a different story.

In reality, there are fewer children today in most American neighborhoods. In fact, the share of population under the age of 18 declined in ~95% of the counties since 2000.

The Bureau’s stats also show that the number of American households reporting that they have children under age 18 has remained roughly static (at ~38 million) … even while the country’s total population grew by ~10% over the decade.

As a result, the share of all U.S. households with children is only about 33%, down from ~36% ten years earlier … while the share of the U.S. population under age 18 is 24%, compared to 26% ten years earlier.

These census figures and others have become grist for many researchers in recent months, with a number of intriguing reports being issued. One, released by the Brookings Institution, focuses on the changing nature of Suburban America. Alan Berube, author of the report, notes that there is a continuing blurring of the once-sharp lines that used to demarcate central cities from the suburbs.

Instead, there now appear to be more similarities between cities and their “inner core” suburbs, rather than between inner and outer suburban communities.

Urban development guru Joel Kotkin sees this development in a larger sociological context — noting that people tend to “self-select” where they live based on “like” characteristics that go beyond mere economic elements to also include psychographic aspects.

In Kotkin’s view, that trend has contributed to the vast differences we see in political and voting behavior in cities, the suburbs, and exurbs. We may have much less overt segregation based on race or ethnic background … but it’s been replaced by a self-segregation based on perspectives and attitudes.

No wonder it seems that people are “talking past each other” — rather than engaging one another — in our national dialogue about the economy and the government’s proper role in guiding it.

Don’t look for this dynamic to change anytime soon.

A mobile society? We’re not there again yet.

U.S. Population MigrationLast year, I blogged about a startling development in the mobility of Americans: fewer of us moved in 2008 than in any year going back decades.

If there was any proof of the recession’s toll on the lives of many Americans, this is surely it. Not only that, it reflects the lost allure of many of the “magnet” states of recent decades, particularly Nevada, Arizona, California and Florida.

Now, new data covering 2009 have just been released by the U.S. Census Bureau. The latest information reveals that more Americans moved in 2009 than in 2008 … but it was just a small uptick.

Moreover, the increase in mobility was almost entirely the result of people moving within their home counties – nearly eight times more prevalent than migrating from state to state.

What does this mean? In many instances, intra-county mobility may be the result of people who have moved in with family or to nearby rental properties after having lost their homes to foreclosure.

And the low rates of mobility in general may reflect the unwillingness or inability of people to move because they owe more on their mortgage than their home’s current value, thanks to the collapse of the housing market.

William Frey, a demographer and senior fellow at the Brookings Institution, sums it up this way:

“These data show that the great migration slowdown, which began three years ago, shows no signs of revising to normal U.S. patterns. Since labor migration is often seen as the grease that spurs the flow of goods, capital and job creation, these new numbers are not encouraging.”

Mobility almost always declines during periods of economic hardship. But it’s now clearer than ever that this particular recession has caused the biggest drop in mobility rates America has seen since the days of the Great Depression.