Your head has a thick red line

January 4, 2022 7:48 PM

Everyone knows 50% of Canadians live below this red line. What my question presupposes is, a percentage of the United States population lives above the same parallel. What is that percentage?
posted by michaelh to Society & Culture (12 answers total)

American Latitude gets you partly there, without much precision. The process for recreating this seems somewhat involved (discussed at the end of the article) but the steps are there.
posted by wemayfreeze at 8:08 PM on January 4, 2022

The current median center of population is sitting on 38°18' according to this map.
posted by wikipedia brown boy detective at 8:11 PM on January 4, 2022

Well, most of that territory maps pretty neatly on to states, and is largely desolate as hell. 300,000 in the UP, vanishingly few in northern Maine, maybe 500,000 in Northern Wisconsin (generously) and the same in Northern Minnesota, 750k in ND, 1M in Montana (probably safe to ignore the bits South), maybe 100k in panhandle ID, 7.5M in WA, and 730k in Alaska. With all the uncertainties in my quick guesses, probably 11M, which is, give or take, 3% of the US pop.
posted by wotsac at 8:25 PM on January 4, 2022 [3 favorites]

Oh, and Portland, OR is centered above the line, but I'd imagine a lot of suburban Portland is cut off. You probably pick up enough people to push it to 4%
posted by wotsac at 8:34 PM on January 4, 2022

I'd get the list of counties (or the MSAs) for Maine, Oregon, Michigan, Wisconsin and Minnesota. For example, I would guess over a million for that part of Minnesota as it holds Duluth, St. Cloud and Moorhead.
posted by soelo at 8:51 PM on January 4, 2022

This should be estimable down to the census block level of accuracy for 2010 data, at least. You'll need to decide how to treat the census blocks cut by the line. Do you count them in, count them out, or make the decision based on whether their centroid is above or below the line? I would probably do that last one, but results will vary depending on your method. Also, is the line at 45°42′N exactly, or is there a more precise value to be used?

I would grab the files from here for each state: https://www.census.gov/geographies/mapping-files/2010/geo/tiger-data.html, open them up in a GIS, and then either select by attributes on their centroid coordinate or else create the line and select by location against that.

I'll probably take a crack at this for fun if nobody else posts a precise answer, or has a better data source.
posted by agentofselection at 9:09 PM on January 4, 2022 [1 favorite]

Okay, using the 2010 census data (this would be findable for 2020 but it would be more work for me), I got a population of 9,726,705 living in census blocks with their centroid north of 45.7°N latitude, or 3.15% of the 2010 population of 308,745,538.
posted by agentofselection at 9:59 PM on January 4, 2022 [4 favorites]

Oh crap, I forgot about Alaska. Make that 10,436,939 or 3.38%. Sorry Alaskans!
posted by agentofselection at 10:02 PM on January 4, 2022 [7 favorites]

wotsac's estimates were pretty good, but Portland is entirely below the line, as is St. Cloud.
posted by agentofselection at 10:08 PM on January 4, 2022

A Fermi Medal for wotsac's good enough quick enough answer?
posted by BobTheScientist at 12:11 AM on January 5, 2022 [3 favorites]

A Fermi Medal for wotsac's good enough quick enough answer?

It took me a few searches to SWYDT. It’s a deeper cut than I expected.
posted by jon1270 at 4:41 AM on January 5, 2022

Ah, I misread the latitude specification of the line when including Portland. It probably wouldn't have happened if I wasn't on to my phone. The other main source of difference was that I was working from Google which has the 2020 numbers.

This mostly leaves us with the question (which was addressed on ask within the last year or so iirc) why do so many people live in Alberta.
posted by wotsac at 7:13 AM on January 5, 2022