Talk:Mean center of the United States population

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Alaska & Hawaii[edit]

The addition of Alaska and Hawaii to the union had the effect of moving the center about two miles farther south and about ten miles farther west for 1960.

Huh? Shouldn't the addition of Alaska move it north? Or is Hawaii far enough south that it balances out?

Hawaii is pretty far south. And don't forget that twice as many people live in Hawaii as Alaska.


A map showing the movement over time would be really neat for all non-Americans as the names of the counties mean next to nothing to us. Lisiate 00:16, 13 Feb 2004 (UTC)

A map has been added. —Bkell 04:04, 7 Apr 2004 (UTC)
Thanks for that, nice map. Lisiate 20:39, 7 Apr 2004 (UTC)

West Virginia[edit]

The population centers of the United States between 1820 and 1860 were never really in West Virginia, as West Virginia did not exist at the time. I have added a note at the bottom explaining this fact, because changing the tags for each of the counties would result in some confusion. I felt that it was better to explain in a note than to mess with the County tags, which are neatly arranged. Uniuni 15:27, 16 November 2006 (UTC)Reply[reply]

Air Conditioning[edit]

Could someone explain to me how exactly is the number of air conditioners related to population growth? Seems like an explanation of the mating habits of mice through quantum physics and the number of butterflies in France... Halibutt 23:12, 3 December 2005 (UTC)Reply[reply]

I think the reasoning is that the availability of air conditioning increased migration southwards. Before then many found the climate too unpleasant. Lisiate 20:28, 4 December 2005 (UTC)Reply[reply]
Yeah, I really don't think that air conditioning part belongs in this article. If there is a connection between population migration and airconditioning, the article should state so. Also, the map shows that even with the advent of air conditioning, there was no immediate or gradual shift in population. It should also be noted that even if airconditioning was available, it was still prohibitively expensive in the 40s. I find it doubtful that people would base their decisions to move on the availability of air conditioning. The East Coast is hot in the summer from Boston to Miami, and plenty of people lived in the Southeast before airconditioning. If the author of that portion believes that there is a correlation, please expand and cite sources. In any case, a such a theory does not belong in the opening paragraph. I suggest that the portion be removed or at least moved to the bottom of the article. Taco325i 01:18, 15 April 2006 (UTC)Reply[reply]
Air conditioning may be related to it. However, I suspect that the civil rights movement and the impression that the South had finally stopped being a 19th-century holdover may have made a difference in persuading northerners to move south as well. Does anyone actually know of any studies on this?RatatoskLemur 22:40, 5 April 2008 (UTC)Reply[reply]
There's been lots written on the effects of air conditioning on the demographics of the south. The article on Houston, Texas mentions it (with citations) as the primary reason for their postwar boom. Polsby mentions it in his book on the evolution of Congress (shifting of electoral votes) [1]. Even the "19th century holdover" could be explained by the weather. The deep south without air conditioning is just not a good place for cities and factories. Its not just Houston, Dallas and Phoenix... this also includes eastern cities like Atlanta and Miami each of which have seen enormous growth in their metro areas since WWII. Perhaps it doesn't need top billing, but its not a joke. DavidRF (talk) 04:38, 21 July 2008 (UTC)Reply[reply]


I would like to see this page include information explaining how mean center is calulated. (ie: formulas)


this cited source has some explaination of this, but maybe its to much yet for this small article. plus I don't know how to make formula's ;-)
The center of population computed by the Census Bureau is the point whose latitude (φ ) and longitude (λ ) satisfy the equations mentioned in the source.
Stated in less mathematical form, the latitude of the center of population was determined by multiplying the population of each unit of area by the latitude of its population center, then adding all these products and dividing this total by the total population of the United States. The result is the latitude of the population center.
East-west distances were measured, or computed, in substantially the same manner, but with the inclusion of a correction for latitude. For these distances, a degree of longitude at the equator was the unit of measurement. East-west distances along the equator could be measured in degrees, but any east-west degree distance north of the equator -- where all the United States is located -- had to be adjusted to recognize the convergence of meridians toward the poles. This adjustment required that each east-west distance, stated in degrees of longitude, be multiplied by the cosine of the latitude. This mathematical relationship is precise for a sphere and a very close approximation for the earth.
The computation required that the longitude of each of the thousands of selected points be multiplied by the cosine of the latitude of the point and by the population associated with the point. These products were added and divided by the sum of the products for the same thousands of points, each of which was obtained by multiplying the cosine of the latitude of a point by the appropriate population figure. The result was the longitude of the center of population. IsFari (talk) 17:17, 14 August 2008 (UTC)Reply[reply]
Maybe we could include this statement in a simpler form. Essentially, it's a question of specifying which map projection is used in the already quoted USCB explanation. From the info you've found, it would appear to be the sinusoidal projection. What do you think? -- Smjg (talk) 18:26, 24 August 2008 (UTC)Reply[reply]

Flaws in Census formula?[edit]

This article points out flaws in the Census Bureau's formula and presents a more accurate way of determining the mean. But why isn't it more widely used? (talk) 03:28, 28 February 2008 (UTC)Reply[reply]

Climatological center of population[edit]

Is it possible to calculate the climatological center of population - on average, what annual temperature and precipitation do Americans enjoy? —Preceding unsigned comment added by Comrade Sephiroth (talkcontribs) 17:55, 2 April 2008 (UTC)Reply[reply]

If its possible, it most likely has been done, so find the source and include it, but not in this article, because it is off topic. IsFari (talk) 16:53, 14 August 2008 (UTC)Reply[reply]


I included coordinates for all the calculated mean centers of US population in a tabular form, but now all these coords also seem to show at the top-right corners of the article. Anyone knows how to fix this ? IsFari (talk) 16:54, 14 August 2008 (UTC)Reply[reply]

No Howard County in 1800[edit]

According to the Howard County, Maryland article Howard County did not exist in 1800 (depending on the exact definition of county, it is either in the 1830s or 1850s. I suggest that it be changed to Anne Arundel County, Maryland (now in Howard County, Maryland).(The bolding is to set of the proposed text, here on the talk page)Naraht (talk) 19:23, 31 December 2008 (UTC)Reply[reply]

There are also similar problems with 1830 being Grant County, Virginia (see Grant County, West Virginia) and 1840 Upshur County, Virginia (see Upshur County, West Virginia).

For 1830, there *never* was a Grant County, Virginia (it was created in 1866 by the State Government of *West* Virginia) and Upshur county was created in 1851 from three different counties. Research will be needed to find out which of the three counties that Upshur was formed from included the mean center point in 1840 and what county included the 1830 midpoint.Naraht (talk) 19:36, 31 December 2008 (UTC)Reply[reply]

OK, I've checked with the Upshur County library and the Upshur County Historical Society. According to the head of the Upshur County Historical Society, the Geographical Center is in the unincorporated community of Lorentz and that Lorentz was part of Lewis County, West Virginia prior to the formation of Upshur County. (along with 95% of the rest of Upshur County.) This information is also available in a published source "At Every Crossroad: A Study Of Upshur County Communities" by Noel W. Tenney.

And Grant County, Virginia was entirely formed out of Hardy County, Virginia, (see for an animated map of the history of counties in Virginia, in addition to the Grant County, West Virginia article.

So [[Hardy County, Virginia|Hardy County, West Virginia]] (now in [[Grant County, West Virginia]]) for 1830 and [[Lewis County, Virginia|Lewis County, West Virginia]] (now in [[Upshur County, West Virginia]]) for 1840? Naraht (talk) 20:17, 31 December 2008 (UTC)Reply[reply]


Before the 1870 census, how were slaves counted for the purpose of waiting? Three-fifths, same weighting, or not counted at all? —Preceding unsigned comment added by (talk) 19:14, 12 January 2010 (UTC)Reply[reply]


How long is it until the statiscs for that decade is churned through. BTW Any rumours to where the centrepoint will end up? —Preceding unsigned comment added by (talk) 08:15, 16 July 2010 (UTC)Reply[reply]

  • The center for the 200 census was released in April of 2001 so we should not expect a result from the 2010 census before early 2011. Eluchil404 (talk) 04:05, 2 August 2010 (UTC)Reply[reply]

2010 Calculated —Preceding unsigned comment added by (talk) 18:36, 21 December 2010 (UTC)Reply[reply]

Article on wikipedian who did the 2010 calculation[edit]

The St. Louis Post-Dispatch today interviews the person who claims to have behind the December 21 edit that named Plato the center. The edit was added anonymously but the i.p. address goes back to his home county in New Jersey.Americasroof (talk) 16:24, 3 April 2011 (UTC)Reply[reply]


I was wondering whether someone could pretty please calculate the distance the centre point "moved" from time to time. I mean, the great-circle distance between the 1790 and the 1800 point, then 1800 to 1810, and so on. In a sense, this would be a measure of how much people moved around in that decade. (talk) 07:43, 18 April 2011 (UTC)Reply[reply]


It would seem reasonable to mention that the median center of population would be where you can divide the population in half, rather than the mean center, which would give more weight to farther away populations on the west coast or farther, dragging the point west of where the median is (talk) 17:44, 26 May 2011 (UTC)Reply[reply]

Meaningless citation[edit]

There were two citations in the article whose full content was "Alex Zakrewsky, Principal Planner, Middlesex County New Jersey Office of Planning." If this refers to a published document of some kind, it is not at all obvious. Apparently this has something to do with the following newspaper article: "How a N.J. man put Plato, Mo., on the map before the census bureau. Todd C. Frankel. Knight-Ridder/Tribune Business News, 2011-04-03." Anyone is invited to figure out whether there is a WP:RS here that should be cited in the article. (Pinging Saucy as well.) --JBL (talk) 15:40, 27 July 2021 (UTC)Reply[reply]

This is probably the same article as the St. Louis Post-Dispatch article mentioned above. --JBL (talk) 15:42, 27 July 2021 (UTC)Reply[reply]
@JayBeeEll: I've Googled "mean population center 2020", and the only thing I was able to find was this map from the University of Virginia. It's a projected result and not the actual result. It seems to be roughly similar to what's in the article, but it's not at all precise.
The article you gave says that Alex Zakrewsky calculated the 2010 mean population center early using incomplete data, which his colleague then put on Wikipedia. It's possible that they've done this again for 2020. I'm sure that's against the original research policy though. Saucy[talkcontribs] 08:20, 28 July 2021 (UTC)Reply[reply]
I agree. --JBL (talk) 11:57, 28 July 2021 (UTC)Reply[reply]

I am hereby appealing to the editors of this page to allow for the publication of my 2020 estimated US population centroid (center) calculation. My contention is that, since the source of my estimation is a conceptually simple calculation involving only the basic arithmetic functions of addition, subtraction, multiplication, and division, it should be allowed under Wikipedia's "Routine Calculations" "Basic Arithmetic" clause, thereby exempting it from Wikipedia's "Original Research" prohibition.

I believe that my annual estimated and projected centroid cacluations have added significant value to this Wikipedia page over the last decade. These calculations have offered a unique real-time summary of the changing settlement patterns in the United States over the years, and have gained acceptance from various researchers. The veracity of my method was first confirmed by comparison of my 2010 predicted centroid to the US Census Bureau's official centroid calculation in 2010. I believe it will almost certainly be re-confirmed once the Bureau releases its centroid calculation for 2020 in coming weeks.

With this message I hope to elicit support from the editors of this page to allow for the publication of my 2020 US population centroid calculated estimate, as well as subsequent annual calculated estimates and projections.

Thank you for your consideration of this matter! — Preceding unsigned comment added by Alex.zakrewsky (talkcontribs) 23:11, September 18, 2021 (UTC)

The calculation does not strike me as being either routine or basic. This is not the "adding numbers, converting units, or calculating a person's age" referred to in WP:CALC.
I'm certain you're confident in your ability to project this; but Wikipedia is not the correct forum in which material like this is published for the first time. If you are ever published elsewhere, in a WP:RS, we could always add it with a citation to that source. TJRC (talk) 00:06, 19 September 2021 (UTC)Reply[reply]

Here's a report about my 2020 centroid estimation: (talk) 01:45, 16 November 2021 (UTC)Reply[reply]

Distance Calculation[edit]

Some (or all?) of the listed distances between centroids are too long when compared to published US Census data and also lat/long distance calculators available on the internet. Can someone please look into this issue and correct erroneous entries? Thanks! Alex.zakrewsky (talk) 14:32, 27 September 2021 (UTC)Reply[reply]

Imminent US Census Bureau Release: 2020 US Population Centroid[edit]

I'm excited to know that the US Census Bureau is about to release its 2020 US Population Centroid location.

I believe that this data release will be notable because it will show an historic slowdown in centroid movement, probably the slowest since the 1910-1920 period as an aging population, ongoing economic difficulties, and the impact of the pandemic work to reduce the means and reason for Americans to move.

Using a method validated in predicting the location of the 2010 US population center, my estimation for the location of the 2020 centroid is: 37.410844 N; 92.364605 W.

This position is 12.83 miles/20.65 kilometers southwest of the 2010 centroid.

This spot is located in Wright County, MO, about 10 miles southwest of Plato, MO and 13.63 miles northeast of Hartville, MO. It remains closer to Plato than Hartville, but I’m thinking that the Bureau may opt to name Hartville the center given its symbolic name. We’ll see.

Judging from past performance, this estimate should be within a mile or two of the official position (that’s the best I can do because I’m working with state-level data). I’ll let you know exactly how far off once the Census calculation is released.


Alex.zakrewsky (talk) 17:15, 29 September 2021 (UTC)Reply[reply]