Tag Archives: population

Disagreement on whether there are 7 billion people on earth just yet

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There have been a number of recent stories about how the world’s population has reached 7 billion. Interestingly, not everyone agrees that this has happened yet:

According to United Nations demographers, 6,999,999,999 other Earthlings potentially felt the same way on Monday when the world’s population topped seven billion. But if you’d rather go by the United States Census Bureau’s projections, you’ve got some breathing room. The bureau estimates that even with the world’s population increasing by 215,120 a day, it won’t reach seven billion for about four months.

How do the dueling demographic experts reconcile a difference, as of Monday, of 28 million, which is more than all the people in Saudi Arabia?

They don’t.

“No one can know the exact number of people on the globe,” Gerhard Heilig, chief of the population estimates and projections section of the United Nations Population Division, acknowledges.

Even the best individual government censuses have a margin of error of at least 1 percent, he said, which would translate in the global aggregation to “a window of uncertainty of six months before or six months after Oct. 31.” An error margin of even as little as 2 percent would mean that Monday’s estimate of seven billion actually was 56 million off (which is more people than were counted in South Africa).

Figuring this out is not an easy task. It requires a central group to tabulate results from all of the countries around the world. Could there be a difference in the reliability and validity of the results across nations? For example, can we trust population counts from honed operations in the United States and other Western nations more than counts from Third World countries? (I wish the article went into this: how accurate are population figures from different countries? How big might the margins of errors be?) I’ve seen this before when doing some research in graduate school on suicide figures that the United Nations has collected – in the period I was looking at, roughly 1950 to 1970, some countries didn’t report, some had rougher estimates, and countries could have different definitions about what constitutes a suicide. Absolute population counts should be more straight forward but I imagine there could be a number of complications.

Will we get another round of news stories when the Census Bureau says we have hit 7 billion? I wonder if the perceived global authority of the United Nations versus that of the Census Bureau plays a role. For example, did the New York Times report the 7 billion figure as front-page news and then print this caveat story later in the news section?

A final note: the story ends by suggesting the two estimates are not that far off. If we could be so lucky that all of our estimates have only a 1% margin of error, science would benefit greatly. But it is a reminder that official figures are estimates, not 100% counts of social phenomenon.

Is the American Sun Belt boom over?

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One of the biggest changes in the American population in the last sixty years has been the migration to the Sun Belt. But new data suggests that this boom may have come to an end:

Between 2007 and 2010, Florida lost more people to internal migration than it gained, for the first time since the 1940s. Nevada, too, which had been growing for decades, had a net migration loss of 30,000 in 2009. And Arizona had a net gain of just 5000, way down from 90,000 five years before.

Meanwhile, New York and California both saw their net losses shrink in 2009 by more than half since 2005.

The analysis, based on Census Bureau and IRS data, was conducted by the Carsey Institute at the University of New Hampshire.

What explains the shift? The Sun Belt states, of course, were hit hard by the housing bust that helped trigger the recession and its aftermath. The early aughts housing boom was responsible for much of the growth in places like Clark County, Nev., and Maricopa County, Ariz. in the first place.

But just as important, migration as a whole, which has been on the wane for three decades, has really tailed off since the downturn began.

The economic crisis has limited mobility across the United States, particularly for the less wealthy who are then more tied to existing jobs and homes.

It will be interesting to see whether this trend continues or (1) the Sun Belt will grow again in the future or, in a longer shot, (2) older cities in the Midwest and Northeast (“Rust Belt”) regain some of the population that shifted south and west. In other words, once people have some more freedom to move, what will they choose to do and what social forces will push or pull them in certain directions?

Declining rural population in US

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While the percentage of Americans living in the suburbs has hit a high of 51 percent and 33 percent of Americans live in cities, an all-time low of 16 percent of the population now lives in rural areas:

The latest 2010 census numbers hint at an emerging America where, by midcentury, city boundaries become indistinct and rural areas grow ever less relevant. Many communities could shrink to virtual ghost towns as they shutter businesses and close down schools, demographers say.

More metro areas are booming into sprawling megalopolises. Barring fresh investment that could bring jobs, however, large swaths of the Great Plains and Appalachia, along with parts of Arkansas, Mississippi and North Texas, could face significant population declines…

The share of people in rural areas over the past decade fell to 16 percent, passing the previous low of 20 percent in 2000. The rural share is expected to drop further as the U.S. population balloons from 309 million to 400 million by midcentury, leading people to crowd cities and suburbs and fill in the open spaces around them.

In 1910, the population share of rural America was 72 percent. Such areas remained home to a majority of Americans until 1950, amid post-World War II economic expansion and the baby boom.

If people were asked to think about the biggest changes in the last 100 years, few might cite this important change: America has shifted from a majority rural population to a majority suburban/urban population. The reasons for this have been well-documented but it is still a large shift away from small towns and farms to suburbs and cities. This has impacted all areas of life: politics, economics, housing, workplaces, families, schools, and more.

It will be interesting to see how rural areas and communities are able or not able to hold on. For example, one area where this gets interesting is healthcare: with more hospitals and organizations consolidating and new regulations coming, who will want to continue to offer rural care?

Except more communities to challenge 2010 Census counts

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Amidst an economic crisis that has also affected many municipal budgets, expect more communities to appeal the 2010 Census counts:

Cities have two years to contest their counts under the Census Bureau’s appeals process, which began this month…

In recent decades, the peak for challenges was 6,600, or 17 percent of all U.S. jurisdictions, in 1990, when the census missed four million people, including five percent of all blacks and Hispanics.

In 2000, roughly 1,200 jurisdictions, or 3 percent, contested the count. The net change due to census challenges that year was just 2,700 people.

Apart from the challenges, analysts later determined the 2000 census had an overcount of 1.3 million people, due mostly to duplicate counts of more affluent whites with multiple residences. About 4.5 million people were ultimately missed, mostly blacks and Hispanics.

Interestingly, the article suggests that while government dollars are behind these challenges, it is also about the “psychological impact” on civic pride. I wonder who exactly will appeal: St. Louis, Chicago, and a host of other Rust Belt cities lost population and New York City didn’t have the population increase that was expected. Since budgets are tight everywhere, could we even get appeals from places like Houston which experienced sizable growth?

It would also be interesting to hear how exactly the Census Bureau adjusts these figures based on subsequent analyses of overcounts and undercounts. This is a reminder that Census figures are not perfect even as many things, including many social science studies based on population proportions calculated in the Census, are based on these figures. I am not suggesting that the Census figures are wrong but rather that it is a very complicated process that is bound to be tweaked some after the first figures are released.

More blacks return to the south

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In the Great Migration that covered much of the 20th century, millions of African-Americans moved to northern cities from the south in search of economic opportunities. With this influx, cities like Chicago were changed dramatically. But a new study suggests that this trend may now be working in reverse as blacks move from northern cities back to the south:

The economic downturn has propelled a striking demographic shift: black New Yorkers, including many who are young and college educated, are heading south.

About 17 percent of the African-Americans who moved to the South from other states in the past decade came from New York, far more than from any other state, according to census data. Of the 44,474 who left New York State in 2009, more than half, or 22,508, went to the South, according to a study conducted by the sociology department of Queens College for The New York Times.

The movement is not limited to New York. The percentage of blacks leaving big cities in the East and in the Midwest and heading to the South is now at the highest levels in decades, demographers say…

Some blacks say they are leaving not only to find jobs, but also because they have soured on race relations.

A few questions pop into my mind:

1. As the article suggests, this sounds like more of an exodus of the middle-class and above. How does this movement back south break down by income and education levels?

2. How exactly does racism and discrimination play into this? Is the situation in the South now preferable to what is happening in major Midwestern and Northwestern cities?

3. How surprising is this considering the population shifts in America over the last few decades to the South and the West?

Increasing numbers of blacks moving to the suburbs

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One of the important shifts revealed in the 2010 Census is the increasing number of minorities in the American suburbs (also see the thoughts of the 2010 Census director here). This is particularly true of blacks who have moved from the city to the suburbs and this raises some concerns about the future of the neighborhoods they are leaving behind:

Taylor’s decision to live outside Chicago makes him part of a shift tracked by the 2010 Census that surprised many demographers and urban planners: He is among hundreds of thousands of blacks who moved away from cities with long histories as centers of African-American life, including Chicago, Oakland, Washington, New Orleans and Detroit…

Chicago’s population fell by 200,418 from 2000 to 2010, and blacks accounted for almost 89% of that drop. Hispanics surpassed blacks as the city’s largest minority group. Meanwhile, Plainfield grew by 204% overall, and its black population soared by more than 2,000%, the fastest rate in the region…

The trend has broad policy implications: As blacks who can afford to live in the suburbs depart, will cities have enough resources to help the low-income blacks left behind? Will the demand for housing be strong enough to support the revitalization of traditionally black inner-city neighborhoods? How will black churches, businesses and cultural institutions be affected? Will traffic congestion worsen because blacks moving to the suburbs keep their jobs in the city?

Roderick Harrison, a sociologist at Howard University in Washington and a former chief of the racial statistics branch of the Census Bureau, says the changes reflect the improving economic status of some African Americans.

Traffic seems to be a lesser issue compared to some of these bigger questions. And these questions are not new: at least since the 1980s, commentators have been asking about what may happen to urban neighborhoods and institutions when middle-class Blacks leave for the suburbs.

We could also ask about how this might change the suburbs. Are we at the point as a society where suburban residents really just care about social class, i.e. being able to buy into the suburbs and maintain a middle-class lifestyle? Or will whites leave suburban neighborhoods when Blacks move in just as they did in urban neighborhoods in the 1950s and 1960s? I wrote earlier about how minorities were fitting into Schaumburg, a noted edge city outside of the Chicago, and a noted historian, Thomas Sugrue, suggested that the move of Blacks to the suburbs in the Detroit region may not be all that positive. I suspect there will be a lot of discussions in suburbs about these changes, often couched in terms of issues like affordable housing (see this example from the wealthy Chicago suburb of Winnetka), property values, and the quality of schools.

It is interesting to note that Plainfield is cited in this particular story: Joliet, Plainfield, Aurora, and the suburban region far southwest of Chicago is a booming area. And if you were curious about the African-American growth in Plainfield, it was 0.8% Black in 2000 (110 out of 13,038) and is roughly 6% Black in 2010 (out of 39,581).

The mean population center of Illinois is close to Chicago but this wasn’t always the case

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The mean population center of Illinois is relatively close to Chicago:

[B]ased on new data from the U.S. Census, the true center point of Illinois’ population is about 70 miles southwest of Chicago’s bustling Magnificent Mile.

Situated in a corn field east of the intersection of U.S. Route 47 and Illinois Route 113 in Grundy County is the point referred to by the census as the Mean Center of Population for Illinois…

The center point can tell a lot about a state.

It can help explain why Illinois has a state government controlled largely by Chicago politicians.

It can help explain how money gets distributed around the state. It can help explain why some issues — say, gun control — can pit rural interests against urban interests.

“Somewhere close to half the population of the state is within 40 miles of the Loop,” Illinois State University geography professor Mike Sublett said.

This is not too surprising: by far, Chicago is the largest city in the state and the population of the Chicago metropolitan region (2009 estimate of the Illinois portion only – not counting Wisconsin and Indiana populations) is just under 8 million while Illinois’ total population is just over 12.8 million (2010 figures).

But the value of such a measure seems to be not exactly where this mean is located but rather how this population mean has shifted over time. The article goes on to note how the population mean wasn’t always so close to Chicago:

In the 1840s, the center point was located east of Springfield, relatively close to Illinois’ geographical center point in the Logan County community of Chestnut.

But, as Chicago began to grow as an urban center, the population center point began its northward trek along a line nearly mirroring what would become Interstate 55.

The 1880 center of the state’s population was on the south side of Bloomington, near U.S. Route 150 south of where State Farm Insurance Cos. has its Illinois regional office complex.

In 1910, the center moved out of McLean County for the first time in 50 years. The new center was in a farm field just a few miles southeast of Pontiac.

The only time it took a break from its northeasterly trek until recently was in 1940, when the center — then located in Livingston County — briefly moved southward…

The northern movement of the center point also has stalled in recent decades. The 2010 center point near south of Morris in Grundy County is somewhat south of the 2000 and 1990 population centers, located just a few miles away.

Sublett attributes the stall to the rapid growth of Chicago’s western suburbs and the loss of population within the state’s largest city.

“The center point has kind of stagnated. It has just been migrating around Grundy County,” Sublett said.

As I’ve written before regarding the US population mean (see here), the population mean measure seems to make the most sense when placed in a historical context so that people can get a quick look at larger population and migration trends.

I wonder how many Chicago area residents know that the bulk of the state’s early population lived in the central and southern portions of the state and it wasn’t really until the 1840s and 1850s that the population of northeastern Illinois really began to grow and tilt the balance of power in the state.

Interactive map of migration into and out of American counties in 2008

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Forbes has an interactive map where you can click on any US county and see where people from that county moved to and where people moving into the county moved from during 2008. Very cool. It would be even better to have more years of data available and be able to see exactly what happened in a place like Cook County in the 2000s with Chicago’s overall population loss.

One complaint: it is hard to distinguish the red lines (outward population movement) from the black lines (inward population movement) when looking at the same county. For example, if you look at the line between DuPage County, IL and Los Angeles County, CA, the line is red even though 252 people moved from LA County to DuPage County and 309 moved in the opposite direction.

h/t Instapundit

Mean population center of US shifts west and south; Midwest may no longer be the heartland

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Geographically, the Midwest is a broad US region between the two coasts and north of the South (as it was constituted in the Civil War). But symbolically, the Midwest is often referred to the as the “heartland” or as where “mainstream” America is, an idea illustrated by a journalist’s claim that a Nixon policy would “play in Peoria” in 1969.

A little-referenced geographic measure, the mean center of population in the United States, is moving west and south again, suggesting that the Midwest will no longer be the American center within several decades:

When the Census Bureau announces a new mean center of population next month, geographers believe it will be placed in or around Texas County, Mo., southwest of the present location in Phelps County, Mo. That would put it on a path to leave the region by midcentury.

“The geography is clearly shifting, with the West beginning to emerge as America’s new heartland,” said Robert Lang, a sociology professor at the University of Nevada-Las Vegas who regularly crunches data to determine the nation’s center. “It’s a pace-setting region that is dominant in population growth but also as a swing point in American politics.”

The last time the U.S. center fell outside the Midwest was 1850, in the eastern territory now known as West Virginia. Its later move to the Midwest bolstered the region as the nation’s cultural heartland in the 20th century, central to U.S. farming and Rust Belt manufacturing sites.

In my mind, the best use of this measure is to track its changing path over time: it has consistently moved West though hasn’t moved that far South. In terms of showing where the “center” is, it is less clear. I would see this type of measure as similar to National Geographic’s recent “most typical face“: it tells us something but is best useful for tracking changes over time.

As for whether this moving mean center of population really means that the Midwest will not be considered the mainstream, this remains to be seen. Could the West really be the new heartland in the eyes of the American people? This would involve a shift in symbols, particularly about what it means to be the “heartland.” Is it where most of the people are, where the swing states are, where there is the most history, where there is the most agriculture, where people are most traditional, or where the people are the most “normal”?

 

Debate over whether cities or suburbs are gaining population

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As the 2010 Census figures trickle out, some commentators are debating about how to interpret this data: “are cities gaining or losing population?” While it seems fairly clear that more people are moving to the suburbs and out of central cities (a long-running American trend), it is less clear if they are moving to the land of single-family homes on the metropolitan fringe or to denser suburban areas (which might be considered cities in their own right).