
How well does population density predict U.S. voting outcomes? - mbostock
https://beta.observablehq.com/@jake-low/how-well-does-population-density-predict-u-s-voting-outcome
======
crazygringo
The "difference" map (third one, green/pink) is one of the clearest, most
intuitive and educational visualizations I've seen in a long time. The "Black
belt" line is so clearly revealing.

I wish "difference from trend" maps were more popular, and more prevalent in
the media -- this would be a tremendous asset in the classroom as well when
teaching statistics.

Kudos!

~~~
mrtnmcc
Interesting how there was a green (bias for Clinton) along the southern
borderline. Do they not like The Wall?

~~~
kibwen
It's not just Texans near the border: "Statewide, 61 percent of Texans oppose
building a wall, while 35 percent support it and 4 percent don’t know or
declined to answer, according to a poll conducted in April by Texas Lyceum, a
nonprofit leadership organization." [https://www.star-
telegram.com/news/state/texas/article152402...](https://www.star-
telegram.com/news/state/texas/article152402734.html) (Link to study, sample
size 1000:
[https://www.texaslyceum.org/page-18205](https://www.texaslyceum.org/page-18205)
)

------
jake-low
Hey, author here. Definitely didn't expect to see this on the front page when
I woke up. A friend posed the question in the title to me last week after
seeing the referenced NYT map, and I spent the last couple evenings making
this notebook to try and answer it.

Let me know if you have any questions; I'll try my best to answer them.

~~~
madcaptenor
I think it would be interesting to see the results of regressing vote against
population density + racial makeup.

~~~
jake-low
I agree. The vote dataset doesn't have demographic breakdowns (I believe it
was created by scraping post-election reports on _The Guardian_, not by
relying on exit polls). But you compare the prediction errors to county-level
data on race (the Census Bureau publishes these numbers) and pose the question
"is the population-density model more wrong in areas of higher diversity?"

------
andrewla
Of note is that graphing the logarithm of population density is really just
the same as taking the difference between log(pop) and log(area). It might be
worth tackling this as a linear model of those two separately rather than
combining them together.

------
madcaptenor
America's ur-choropleths:
[https://kieranhealy.org/blog/archives/2015/06/12/americas-
ur...](https://kieranhealy.org/blog/archives/2015/06/12/americas-ur-
choropleths/)

------
cageface
This is another analysis that proposes a more convincing model (IMO) for the
voting patterns in the US based on colonial history & culture.

[https://www.nytimes.com/2018/07/30/opinion/urban-rural-
unite...](https://www.nytimes.com/2018/07/30/opinion/urban-rural-united-
states-regions-midterms.html)

------
jcfrei
I think the data from Alaska should be excluded, all counties have the same
ratio.

~~~
jake-low
Thanks for pointing that out! It looks like every county in Alaska is just
showing the state-level vote ratio. Might have to do with Alaska having
boroughs instead of counties? I'll look into this later; I've added a
disclaimer at the bottom of the notebook for now.

~~~
crznp
It looks like the data is being pulled from Townhall, which has the same issue
[1]. Wikipedia has seems to have the data [2], though the percentages are a
little different (51.3% for Trump rather than 52.9%). Perhaps it is wrong
because not all land in Alaska is part of a borough, Eg: Nome is listed
separately, but it is just a census area.

Interesting that it seems to have the reverse trend -- Anchorage and Fairbanks
went for Trump while much of the unorganized borough went to Clinton.

[1] -
[https://townhall.com/election/2016/president/ak/county](https://townhall.com/election/2016/president/ak/county)
[2] -
[https://en.wikipedia.org/wiki/United_States_presidential_ele...](https://en.wikipedia.org/wiki/United_States_presidential_election_in_Alaska,_2016)

~~~
tonmcg
I'm the author of the GitHub repo that Jake references and the reason I stated
Alaska totals at the state level is because elections there are administered
at the precinct level, which have no county equivalent.

Alaska's "county equivalents", as the U.S. Census calls them, are known as
Census Areas, Municipalities, and Boroughs. But again, there are no election
data reported at those levels.

See here for more detail:
[https://github.com/tonmcg/US_County_Level_Election_Results_0...](https://github.com/tonmcg/US_County_Level_Election_Results_08-16/issues/2#issuecomment-321474450)

------
clircle
Model looks like it would benefit from a quadratic term based on the scatter
plot

~~~
darkmighty
I'd chose a logistic-like curve to fit (since extrapolating to infinite
population the ratio should approach 1 and 0 population it should approach 0).

~~~
carbocation
I'm actually wondering if the model was fixed to have an intercept at (0, 0).
That line looks way off.

~~~
btilly
I wonder at the same thing. Allow the intercept to change and you'll get a
massively better predictor. That will also stop moderately higher density
counties from being green, and moderately lower density ones from being pink.

------
lemoncucumber
It seems like the takeaway here is that population density only predicts
voting outcomes among white voters.

~~~
gowld
That's a good hypothesis that should be answerable if there is county-level
race data.

Also, how good is "county-level" at correlating to population density? Some
huge cities are their own counties, but are there many counties that have an
urban seat and also outlying areas, with a significant split into two sections
of similar population, but very different population density?

~~~
pchristensen
I would be willing to bet that there's not a single county in the US with a
population density higher than the population density of its largest city.
(obviously city-county mergers like NYC, Indianapolis, Jacksonville, etc would
have a ratio of 1.) Indeed, most counties that have any town of > 20k people
and that are not dominated by a huge city probably fit your criteria.

~~~
madcaptenor
I'm having trouble finding data on this where all the populations are from the
same time, but Forsyth and Gwinnett counties in Georgia _might_ be
counterexamples. (Their largest cities, Cumming and Peachtree Corners
respectively, are hardly cities so much as just bits carved out of North
Atlanta suburban sprawl.)

------
blang
I'm not sure how accurate this data is, but it seems to draw a similar
conclusion:

[https://overflow.solutions/special-projects/each-
congression...](https://overflow.solutions/special-projects/each-
congressional-district-ranked-by-population-density-colored-by-political-
party-of-the-representative/)

------
tareqak
I've actually wondered if having a two-system form of government to deal with
the urban-rural divide would be effective in governing. Basically, a
government for urban-dwellers with one set of tax rates, services, and laws,
and another government with another set of tax rates, services, and laws for
rural-dwellers. There would be a common overarching government over the two
for dealing with common interests e.g. military, international affairs,
necessary infrastructure.

Something that I've wondered as part of this idea is why states after the
original thirteen colonies became geographically larger in size. In hindsight,
it seems much harder to have common interests across a numerically large group
of people spread over a larger physical area.

Afterthought: I forgot to mention that the parts that are urban, and the parts
that rural would have to be re-evaluated over time to see if that
classification still holds or merits changing.

~~~
merpnderp
Hmm, you could call this type of government a federated system. Have it broken
into different states and counties, maybe with local city governments.
Enumerate some powers reserved for each while keeping a central authority to
make sure everyone is assured at least a minimum of rights.

Naw, would never last.

~~~
mcculley
It didn't last.

~~~
politician
Actually, what happened is that the boundaries became immutable concrete while
the population concentrations varied.

At this point, we should redraw all state lines, and raise the number of
elected officials in the House and Senate.

------
superseeplus
How does population density affect the impact of an individual vote?

~~~
curo
I think the left would respond that urban populations are diverse & educated.
And the right would respond that it's hard to preach conservative values of
individual liberty and personal responsibility (e.g., leave me alone, i'll
leave you alone) when people are living on top of one another.

~~~
sonnyblarney
"individual liberty and personal responsibility (e.g., leave me alone, i'll
leave you alone) "

Those are not conservative values, those are libertarian values, we might call
them 'liberal' in the rest of the world (well, kind of, using that phraseology
like 'leave me alone, i leave you alone' is kind of a American
colloquial/populist or crude way of expressing it - in fact it doesn't
describe classical Liberalism very well at all, but nevertheless someone with
that ethos would definitely fall under this camp, and not Conservatism)

Classically Conservative 'values' (though not necessarily politics) are more:
family, community, responsibility towards community, faith, tradition, duty
etc..

Conservative and Libertarian values clash distinctly in the are of 'community'
\- one is individualist, one is instinctively though often not obviously
community oriented.

'Duty' is generally a conservative concept you don't hear much in the
Libertarian leaning crowd.

But it's moot as far as this article is concerned: The data in this article is
highly problematic due to the fact that most newcomers move to the cities, and
so it entirely skews the data.

It's not an argument of 'disperse vs. dense' \- it's really just a proxy for
ethnography.

From the link in the comment above [1]: "population density and percent black
will do a lot to obliterate many a suggestively-patterned map of the United
States. Those two variables aren’t explanations of anything in isolation, but
if it turns out it’s more useful to know one or both of them instead of the
thing you’re plotting, you probably want to reconsider your theory."

[1] [https://kieranhealy.org/blog/archives/2015/06/12/americas-
ur...](https://kieranhealy.org/blog/archives/2015/06/12/americas-ur-
choropleths/)

~~~
jack9
> those are libertarian values

As a libertarian voter, in the USA, I find this kind of position to be
juvenile. They are conservative values, that happen to overlap with
libertarian goals. Libertarian values are neither fundamental (old enough to
be the basis for any other system) nor complete enough to be considered a
value system at all. They are just rough applied values (eg limiting
government is a general preference, not an ideology). Trying to exaggerate
libertarian values to mean something absolute shows a deep misunderstanding of
the movement.

~~~
sonnyblarney
" I find this kind of position to be juvenile. "

Americans often do not understand their own political ideologies, the basis
for them, and use completely the wrong words in describing them.

Libertarianism is ultimately an American flavour of (Classical) Liberalism,
which is quite an old political tradition.

'Freedom of expression' is absolutely _not_ a conservative value, it's
fundamentally Classicaly Liberal.

Capital 'C' Conservatives in the USA may be big on 1st amendment type things,
but it's really not conservative at all.

Liberals would have wanted to abolish the relationship between Church and
State, conservatives would generally not want that, historically.

Liberals pushed for centuries for certain people to be able to have certain
rights, conservatives would have been generally opposed to such things on
political grounds, less so on the basis of values. 'Values' based politics is
a more modern thing.

Even free markets - this is not a conservative thing, it's a Classical Liberal
/ Libertarian thing, which is why the term 'neoliberalism' is sometimes used
to describe super capitalist/free market types. None of that is conservative.

In terms of 'values' \- 'freedom of choice/expression' is fundamentally at
odds with communitarian values and it's more easily understood in issues like
the draft: A conservative would believe that in the event of (legitimate) war,
everyone should do their best, basically sign up to fight. The draft would be
seen as the rational duty of citizens. A libertarian would never accept such a
transgression of their rights - joining the Army under any circumstances would
have to be a matter of conscience.

Angela Merkel is mostly conservative. In larges swaths of Europe they have
compulsory military service even though they are politically more progressive
- it's because they are culturally fairly conservative. Most European nations
have state Churches, i.e. official religions.

In Europe, the 'free market / big business' folks are not called conservatives
(because they aren't), they're called 'Liberals' \- which is what they are.
The left has Social Democracy, Democratic Socialism. The right usually has
Christian/Agrarian Democracy and then maybe some kind of nationalist movement
in there.

I admit though 'personal responsibility' is both a conservative and
Libertarian value. To a conservative, personal responsibility is a community
obligation, righteous members of the community are hearty, productive, and fyi
generous. Christian Democrats ideals are fundamentally communitarian (charity
with no expectation of return is a requirement) and are totally incompatible
with this 'Ayn Rand' stuff about not necessarily having an obligation toward
others. (There's a hint there: you absolutely cannot be a Christian and
Objectivist at the same time, Christians 'serve God' by behaving morally and
by building the community, possibly through self-sacrifice and charitable
work, putting God and the 'greater god' above oneself, whereas Objectivists
pursue their own happiness as a moral obligation - charity is a choice, not an
obligation) Libertarian personal responsibility is more a matter of individual
pragmatism: 'Take care of yourself nobody else will (or should)'.

It's obviously a weird paradox in America that some conservatives value
community and duty (think boy scouts, military service) and at the same time
this penchant for 'absolute freedom'. I believe this is reconciled if you
consider 'democracy' really as the form of freedom they aspire for people of
other nations and that Americans wish for this basic opportunity for all
people - to the point wherein they are willing to fight/sacrifice themselves
for that 'greater good'. And of course on the left, you have artists/creative
types who on one hand talk about sexual liberation and being 'open minded' and
yet who are in 2018 the vanguard of the very illiberal policing appropriate
language, and controlling what is acceptable culturally (i.e. only transgender
actors should play transgender roles), opposing academic views which are
hostile to some ideas etc. etc.. It's definitely weird. Anyhow , in America,
Liberals are often not very liberal, and Conservatives are often not very
conservative at all.

~~~
adamrezich
This is a really good post.

~~~
jack9
> Libertarianism is ultimately an American flavour of (Classical) Liberalism,
> which is quite an old political tradition.

"Ultimately" being a weasel word for redefining it again to meet a particular
ideology.

This is not correct, nor is historical cherry picking a compelling argument
for the viewpoint.

He goes off on yet another tangent after trying to justify the interpretation,
through parallel interpretation. They will continue to be one of the many
people who are convinced they are right, deriding others with more rational
and moderate position, trying to get into arguments to try to justify their
beliefs.

~~~
sonnyblarney
I was replying to a non-factual ad-hominem attack, so I thought it required
more explanation.

Now I'm being attacked again, with a non-factual personal slander.

Lovely.

My post is basically textbook politics, it's not my opinion. I think my
examples are pretty reasonable.

'Libertarianism' is an extension of Classical Liberalism, it's not a
conservative movement (in terms of political ideology) and there's no debate
about that.

'Republicanism' is 100% a Liberal ideal _by definition_. There's no wiggle
room there. To be a 'Republican' literally means to be against the Monarchy or
even Constitutional Monarchy, which is right at the core of Liberalism.

'Pursuit of Liberty' is not a conservative objective, it's Liberal, i.e.
'Classically Liberal'.

The only debate is what some of those words have come to mean through the lens
of pop culture media, and that's all pretty foggy.

'Republican', the party, has little to do anymore with 'Republicanism'.

In particular, 'Liberal' has come to mean 'Left Wing' and 'conservative'
usually 'right wing'. And since there are only two parties in America (and
they are both more or less Liberal), and because party allegiances have
changed, and because Americans don't ever learn political theory in school,
and because the American press confuses the issue even further - it's a mess.

It's nuance, but it's not that complicated.

European political parties especially their naming - are generally more
consistent and clear. When you look at the European political landscape for a
bit, things are easier to grasp. Things start to make more sense.

------
chiefalchemist
One election does not a trend make. But perhaps also looking at previous
elections - national and local - would reveal trends / patterns?

I saw a comment below where the author said the data didn't have demographics.
That's understandable. But what about population change?

This was interesting.

------
cmurf
I grew up in Kansas and up until about 15 years ago it bounced back and forth
between Democrats and Republicans frequently. And in my dad's era, post war,
pretty much everyone was a Democrat, whether urban or rural. And then the
parties have flipped ideologies substantially (Southern Democrats, and then
Nixon-Atwater Southern Strategy Republicans), and even arguably in 2016 you
get a rather substantial 180 degrees with Trump Republicans who suddenly
became anti-globalism (domestic capitalism, global mercantilism).

So on the one hand, you need more data over more elections to see if there's
correlation, but then that adds noise. At a national level, the parties have
sub-parties within them where in consensual democracies they'd be separate
parties, it's not a strictly two party system like you see in majoritarian
democracies. And this is always in flux.

Another source of noise is just the nature of the 2016 presidential election.
Possibly a better source to reduce noise? U.S. senate races. They're statewide
like a presidential race, the term is 6 years, but the lack of national media
hype involved in the campaigns makes them less emotional and the data might be
more stable. The incumbency problem might make it useless.

~~~
leereeves
JFK and FDR still seem like Democrats.

Hoover, Eisenhower, and Teddy still seem like Republicans.

The idea that the parties "switched" is little more than a notion with which
Democrats try to distance themselves from the awful parts of their past.

~~~
maxerickson
The distancing claim is that the racists switched parties, not that the
parties switched ideologies.

Ya know, like Strom.

If you don't think it's kind of obvious which party currently has more members
that think it's fun to race bait or worse, well whatever.

~~~
leereeves
The claim was:

> And then the parties have flipped ideologies substantially

Strom Thurmond was one of three Southern segregationists who switched parties.
The rest of the segregationists remained Democrats, including such famous
names as George Wallace and Robert Byrd.

And the Civil Rights Act had more support from Republicans than from
Democrats.

~~~
maxerickson
You've misread my comment. I responded to you stating that Democrats like to
distance themselves from their past by pointing out that they don't do this
with claims about switching ideologies.

That's why I put the word "distancing" in front of the word "claim".

Does that 3 count include an exhaustive survey of voting Republicans or is it
just sophistry to get people reading the remark to focus on prominent
individuals?

~~~
leereeves
That 3 is the number of politicians who switched. I focus on prominent
individuals because history has recorded their actions, so we can actually
speak factually about their behavior.

Unless you have an exhaustive survey of individuals who switched parties,
let's avoid unfounded (and likely partisan) speculation about what such a
survey might say.

~~~
maxerickson
You started the thread with an assertion that is on the same footing as my
speculation.

~~~
leereeves
That assertion is based on facts, not speculation, and I'm happy to back it up
with as many facts as you like. For example:

In 1976, after the South supposedly supposedly switched allegiance, shortly
after LBJ's (reported) claim that he'd "lost the South for a generation", all
the Southern states except Virginia voted for Carter, a Democrat.

(Apparently there's some doubt about whether LBJ actually said that. The media
may have lied to us again.)

~~~
lawtguy
1976 is the only time since the signing of the Civil Rights Act of 1964 that a
Democrat has won a majority of the south. !976 was definitely not a regular
election. The Democratic candidate was white evangelical southerner. The
Republican candidate was a northerner who had been Nixon's vice president and
had pardoned Nixon. It took pretty extreme circumstances for the south to vote
for a Democrat after 1964.

~~~
leereeves
What are the extreme circumstances there? That the Democrat was a Southerner?
So were Clinton and Gore.

That Ford was closely associated with Nixon and had pardoned him? Why would
the South have cared more about that than the rest of the country? Despite the
pardon, Ford won 27 states, including California, and 48% of the popular vote.

In 68 much of the South voted for Wallace, a Democrat running as an
independent, and Texas voted for the Democrat ticket. In 72 every state save
MA and DC voted for Nixon, so the South doesn't stand out there. Then in 76
the South voted for the Democrat, Carter.

It's not until Reagan that we see the South reliably voting Republican.

------
davidw
Living in close proximity to other people makes you more conscious of
externalities.

~~~
jfoutz
"It predicted that Tarrant county, with 904 people per km², would support
Clinton, while Zavala County, with 3.6 people per km², would support Trump. In
fact, the reverse was true."

~~~
adrr
Tarrant is a very fast-growing county. The population has doubled over 20
years. Be interesting to see 2008 and 2012 results to see if there is a trend.

------
kodablah
Naive question, can we just "backfit" sets of county metrics based on results
of the last few elections to determine which ones have effect? Surely with a
large enough set of metrics (i.e. all combinations of density, race, and
gender), a large enough sample size (all counties in this case), and over
multiple elections (albeit all reasonably recent to avoid historical shifts),
we can determine the set of metrics which are the highest predictors with the
fewest exceptions without appearing to rely too much on correlation.

------
jrockway
The biggest question I have is, did population density change between 2008 and
2016 to skew the result of the elections in different directions?

My intuition is that it did not, and thus it doesn't predict much.

~~~
Gibbon1
The error with that thinking is that an election is a one bit sampling
function. Small shifts can flip the result.

This is why I'm dubious about polls as a way of guiding campaigns.

------
c3534l
It seems pretty obvious to me that the line is a bit off. If you allowed it to
have a negative y-intercept or allowed some kind of an S-curve you'd reduce
the error dramatically.

------
ArnoVW
The Economist had an interesting article this summer about this subject,
covering it from historical, statistical and political angles :
[https://www.economist.com/briefing/2018/07/12/americas-
elect...](https://www.economist.com/briefing/2018/07/12/americas-electoral-
system-gives-the-republicans-advantages-over-democrats)

------
cmpolis
What's up with the line of points at y=0.3772? seems anomalous

~~~
jake-low
It's Alaska, as noted in the footnotes of the article; I think each borough is
showing the vote ratio for the whole state rather than the borough-level data.
Sorry about that; I'll make some time to look into it later.

------
DougN7
This is really interesting. Nice job!

Something I’ve always wondered though is whether it’s cause or effect. In
other words, does living in high density areas make liberal causes more
important to a person, or is a liberal person more drawn to high density (big
cities). And the inverse for conservatives.

~~~
rossdavidh
You might be interested in reading "The Big Sort":
[https://www.goodreads.com/book/show/2569072-the-big-
sort](https://www.goodreads.com/book/show/2569072-the-big-sort) The long and
the short of it is, it's both.

------
rmason
There's a factor this research overlooked and that's intensity. Bernie Sanders
won the Michigan primary with high turnout in Detroit. Those voters stayed
home in November and that was the difference.

Even with the swing in Macomb county of Obama Democrats voting for Trump that
was much discussed by the national media it still could have been overcome
with a 2012 turnout level in Detroit. I'd be curious if that was replicated in
other states.

~~~
rossdavidh
My impression: staying home is a way of voting for some people. There are some
(many?) people who have so strongly identified with one party, that when they
are upset with it and want to "vote against" it, they still cannot bring
themselves to vote for another party, as that seems a violation of their core
identity. So, staying home is how they vote for the other party. It only
counts half as much, of course. So, in this example, there might be some black
voters who cannot bring themselves to vote Republican, no matter what, but if
they are upset with the Democratic party they may stay home. Similarly,
Christian conservatives who don't like the Republican candidate may not be
willing to vote Democratic, but they might be willing to skip voting.

Just a hypothesis, of course, I have no data to back that up.

------
ersiees
Did not work on my iPhone 6 in Germany. Saw a lot of: “ RuntimeError: us could
not be resolved“

~~~
jacobolus
Try this one
[https://beta.observablehq.com/d/64da99d0a15ecb6a](https://beta.observablehq.com/d/64da99d0a15ecb6a)

------
jakemor
RuntimeError: us could not be resolved on safari iPhone X :'(

~~~
jacobolus
Try this one
[https://beta.observablehq.com/d/64da99d0a15ecb6a](https://beta.observablehq.com/d/64da99d0a15ecb6a)

------
adverbly
What is up with Richmond county? Quite the outlier there.

------
moultano
Does a logistic fit work better?

------
ianai
TLDR: “this exercise demonstrates what we already know: voter preference is
complicated, and while it is affected by population density, there are too
many other factors for that metric alone to be a good predictor”

~~~
wool_gather
Did we actually _know_ that before investigating, or did we just have a guess?

~~~
ianai
That’s a quote from the article.

------
pishpash
Why would one try to fit a line to this?

------
bsherrill
Population density = media consumption

~~~
jrockway
In what direction? People in New York are all walking around reading
Instagram, people in Kansas are sitting at home watching Fox News. Which group
consumes more is not clear to me.

------
astrodust
How well does the average number of bullet holes in road signs predict US
voting outcomes?

How well does the number of Pumpkin Spice lattes sold per capita predict US
voting outcomes?

