Friday 25 February 2011

Moving West, WCYDWT

Just a few miles south of I-44 near Ft Leonard Wood lies the little town of Plato Missouri, population 65. If you head south out of town on county road 5870 (Turley Road) for about 1/2 a mile you come to a sharp right followed in a few hundred feet by a sharp left. At that moment you are at the side of Roubideau Creek, and very near the population center of the United States. (I estimate it to be across the creek in a field on the other side.)

Every ten years a new population center of the country is determined by geographers at the Federal Census Bureau, using data from the latest recently completed national census.

The Center for Land Use Interpretation (your tax dollars at work) report:
The official Center of Population for the USA is determined mathematically as the place where an imaginary, flat, weightless and rigid map of the United States would balance perfectly if all the 310,570,000 or so residents counted in the 2010 census were of identical weight. The previous official population center of the USA, based on the results of the 2000 US Census, is 2.8 miles east of Edgar Springs, Missouri. It moved 35 miles west-southwest from a point near Steelville, Missouri (its position determined by the 1990 census). The new Population Center, near Plato, is 25 miles southwest of Edgar Springs, reflecting the general migration of population from the wintery urban northeast to the sunbelt of the Southwest. Currently the federal government is working with local representatives at Plato to determine a location for a monument to mark the new center in a place that is accessible to the public.

A nice map from Wikipedia shows the population center for every census since the first census in 1790.

It raises several interesting questions for a multi-curricular investigation.. for example, note the change from 1920-1930 or 1940-1950 as compared to 1930-1940. Now I read "The Grapes of Wrath", and all those Okies heading west should have made a big jump, ...shouldn't it? But it seems prosperity brought a greater incentive to move west than poverty.

And what accounts for the really small jump from 1910 to 1920? Yes there was a war on...but there was in the forties also.

If you are interested in expanding this analysis, you might explore another site operated by USA Today which has separate offerings for population centers of various descriptions (whites, Blacks, American Indians (NOT Oklahoma if that was your guess)etc..). You can also pop open a page with statistics about the various states and the nation as a whole, but it doesn't include the 2010 census results. The data includes some interesting (read scary) data on poverty numbers by age..

So, the next time you are cruising west on 44 across Missouri, set the old Tom Tom on Plato, Missouri and swing by. Cannon's Cafe on Hwy 32 in Plato should have Coffee on, and if not Weber's is just up the road. Can't vouch for the pie yet, but when I go through they will almost certainly give me a big slice for free for this unsolicited plug. Are you listening Plato?

I also found an animated link for US centers, but only up to 2000..  At the same site I found another animation for the MEDIAN center of population of the US.  Very different type of motion, and the current median is located well east of the average position... still back in Indiana (although the 2010 census may put it over the line into Illinois, or maybe down into Kentucky... I'm rooting for a location that will be, like me, near beautiful Possom Trot, Ky. 
Addendum:  After Arjen's post (below) I found the following on a Wikipedia page about Centers of population:


In Finland, the point of minimum aggregate travel is located in the municipality of Hauho.[4] It is moving slightly to the west and south every year because people are moving out of the periphery areas of northern and eastern Finland.


In Germany, the centroid of the population is located in Spangenberg, Hesse close to Kassel.[5]

Great Britain

A centre of population in Great Britain did not move much in the 20th century. In 1901, it was in Rodsley, Derbyshire and in 1911 in Longford. In 1971 it was at Newhall, South Derbyshire and in 2000, it was in Appleby Parva, Leicestershire.


The centroid of population of Japan is in Gifu Prefecture, almost directly north of Nagoya city, and has been moving east south east for the past few decades.[9] More recently, the only large regions in Japan with significant population growth have been in Greater Nagoya and Greater Tokyo.


The demographical center of Sweden (using the median center definition) is Hjortkvarn in Hallsberg Municipality, Örebro county. Between the 1989 and 2007 census the point moved a few kilometres to the south, due to a decreasing population in northern Sweden and immigration to the south.[10]


Arjen Dijksman said...

Interesting, especially about the rate of progression every decade with respect to the historical events. I wonder if such population center maps are also available for other countries, like China, Russia or Canada.

Pat's Blog said...

I know the French have stopped a periodic count of the total populaiton. I'm not sure if the new annual counts are regional in nature or if they use some kind of sample to estimate... are you aware? I know here in England they have a census day every ten years (it's next month in fact)...maybe even I will get to play.

Steven Colyer said...

GOOD Question, Arjen. How long have those places had Censuses?

But why stop there? How about South America, Europe, Africa, and Australia?

Canada? Probably does a Lorenz attractor thing between Montreal and Toronto, starting out east of Montreal, maybe Halifax, and ends well west of Ottawa, but still within 100 miles of the American border at all times.

China? I am bad on Chinese history, so wild guess: centers around Shanghai for most of their history before heading west.

Russia? Probably starts in Khazaria, which is now Chechya, then goes north and west until it's well west of Muscovy and north of Kiev, and is probably a complete mess after that. Unlike the Russians themselves, of course.

Europe? I'm kind of doubting it ever leaves Switzerland or northern Italy, after an initial start around Thrace, but I'm just guessing.

( btw Pat, I have the proof by (allegedly) Theaetetus' that there are only 5 regular polyhedra up on my blog today. )

Anonymous said...

We can add population in one place, we can remove population in one place, or we can move population from one place to another.

It would be interesting to associate individual pairs with one of these phenomena. For example, 1890-1900 shows a very small move west, probably due not to major changes in internal migration, but to a massive surge in immigration to the Northeast.


Dave said...

Hi Pat,
A few years ago I wrote an article about a Calc II lab that I wrote for finding centers of the US—geographic and population. If you're interested, you can find it here: "Centers of the United States," The College Mathematics Journal, 36 (November 2005) No. 5, 366–373. If you don't have access to the CMJ and would like a copy, just let me know.


Pat's Blog said...
This comment has been removed by the author.
Pat's Blog said...


Interesting conjecture... I had no idea, but when I went to check, the decade from 1891-1900 was smaller than the ten year period on either side of it...
1881-90 5,246,613
1891-00 3,687,564
1901-10 8,795,386

Anyone have any suggestions?

Anonymous said...

Peak Southern and Eastern European immigration was in the 1890s.

The Chinese exclusion act is 1880 something.

But that feels thin. Anything else?


Arjen Dijksman said...

Following your addendum and reader's comments, I got interested in all this. There seems to be a whole statistical branch in geography that studies the average displacement on maps. Google scholar "centrography" or related terms returns a wealth of papers on this subject.

Likewise the US population, in Quebec, the population migrated south-west between 1951 and 1971, source: figure 5 of pdf Analyse centrographique de la population du Québec de 1951 à 1971. This paper also shows how such barycentric methods depend on the Pythagoras relation.

In Europe, there are a lot of little villages who boast to be the geographic centre of something (European union, Euro zone...), but I didn't find much data on population barycentres. The reason for that must be indeed that the data come from a variety of national and regional census sources, who don't count at the same dates. This should however be a strategic factor for the place of settlement of companies who aim to be near to their customers.

@Steven. You talk about Lorenz attractor. This made me think that physical forces are used as models to investigate such shifts of populations. Economic attraction and potential, cultural attraction, diffusion into open spaces, political forces and revolutions, wars, peace, weather, natural disasters ...

Steven Colyer said...
This comment has been removed by the author.
Steven Colyer said...

I should have said Strange attractor or just plain Attractor, attractors themselves being a subset of Chaos theory in Maths, which I prefer calling Order-in-Chaos Theory, because that's more descriptive. ;-)

Order-In-Chaos is so bleeping young and fascinates me endlessly. I don't know but I think there aren't enough attempts to incorporate it into fundamental Physics, although I heard there were early attempts with mixed results.

But those were early! The whole field is young (Edward Lorenz came up with his attractor in 1963 for example) and there's much work to be done. One of my (too many) dreams is to get up to speed and possibly help out in that regard someday. Hey, if you know of a great blog on Chaos then do tell, and I'll add it to my feed.

I was also thinking of it in terms of European population shifts, with its much longer history than that of America's, I suspect Europe's tended to move around quite a bit, unlike the USA's straight-ish line.

America's is very cool, though. Note the way it deviates very little from North to South, and looks pretty steady from East to West. That makes sense when you consider the twin origins of our EuroPopulation having been Plymouth and Jamestown. I was surprised though that it holds so steady.

I think in the future you'll be seeing it turn to the Southwest quite a bit, as Americans are drawn in waves to the Southern Cali to Texas region. Very nice climate, and very dry so there's little humidity as in Florida. The older we get the less we like humidity, and with the Boomers retiring or about to, I expect the 2020 shift will be greater yet.

Anonymous said...

Nicely tied together! Given n villages, we can make them each the midpoint of one side of an n-gon, and actually find the vertices of the n-gon.

Everyone's in the middle of something!