Claim: Disease-transmission model forecasts election outcomes


Election model treats political influence like a contagion


Research News

[click view more link to watch video. ~cr]



  • New model treats decided voters as ‘infected’ and undecided voters as ‘susceptible’ to infection
  • Democratic and Republican ‘diseases’ propagate through a population, ‘infecting’ undecided voters
  • Model introduces the possibility of asymmetric relationships, or influence, among states
  • As of today (Oct. 29), the model forecasts a victory for Biden 89.03% of the time

EVANSTON, Ill. — A new election forecasting approach uses mathematical modeling to describe how voters in different states may influence each other during an election year.

To simulate how interactions between voters may play a role in the upcoming presidential, gubernatorial and senatorial elections, a Northwestern University research team is adapting a model that is commonly used to study infectious diseases.

The model treats decided voters as “infected” and undecided voters as “susceptible” to infection. Two “diseases” (namely, Democratic and Republican voting inclinations) propagate through a population, “infecting” (or influencing) undecided individuals.

“Experts like the team at FiveThirtyEight account for the fact that, if you misidentify how Pennsylvania will vote, then you might also misidentify how Ohio will vote because those states have some similar features,” said Northwestern’s Alexandria Volkening, who leads the research. “Such symmetric relationships between states are important. Using a disease-transmission model, we also introduce the possibility of asymmetric relationships, or influence. For example, a candidate campaigning in Florida might be featured in the news in Ohio and influence the voters there.”

The research published online yesterday in SIAM Review. Viewers can follow the 2020 forecast here.

Volkening is an NSF-Simons Fellow in Northwestern’s NSF-Simons Center for Quantitative Biology and in the McCormick School of Engineering’s Department of Engineering Sciences and Applied Mathematics. The paper’s coauthors are Daniel Linder of Augusta University, Mason Porter of UCLA and Grzegorz Rempala of The Ohio State University. Their 2020 forecasts are in collaboration with Volkening’s students (Samuel Chian, William He and Christopher Lee), who are undergraduates in the McCormick School of Engineering.

The project began when Volkening and her coauthors aimed to better understand election forecasting.

“My background is not in election forecasting,” said Volkening, who often applies math to biological questions. “But I’m interested in problems in complex systems, where individuals come together to create group dynamics. Mathematical models can be used to describe the behavior of cells in developmental-biology applications and the interactions of voters leading up to elections.”

Volkening and her team wanted to use a data-driven, mathematical modeling approach. They settled on adapting a so-called “susceptible-infected-susceptible” compartmental model that is typically used to study the propagation of illnesses such as the flu.

By adapting this model to account for two “diseases” (Democratic and Republican voting inclinations), the researchers simulated how decided voters may influence undecided voters. A Republican voter speaking to an undecided voter, for example, may influence them to become Republican. In another scenario, former Vice President Joe Biden could attend a campaign event that influences undecided voters.

“In the future, we may be able to tease out how states are influencing each other and pinpoint more influential states,” Volkening said. “We’d like to explore how interactions among states change over time.”

To generate each of their 2020 forecasts, the researchers use polling data from FiveThirtyEight to simulate 10,000 potential election outcomes. At the time of this article, the model forecasts a victory for Biden 89.03% of the time, and a victory for President Donald Trump 10.78% of the time.

“It’s been exciting to run the model continuously over time,” said He, a sophomore studying applied mathematics and statistics. “We don’t just have a single forecast. We update our website regularly, so we can track how opinions are changing.”

Although 89% may sound like Biden has a high chance of winning the election, Volkening is quick to point out that voter turnout and undecided voters could change this.

“In many states, the margin of victory that we are forecasting for Biden is lower than the percentage of undecided voters,” she said. “If undecided voters turn out strongly for Trump, we could certainly see a Republican outcome.”


The paper, “Forecasting elections using compartmental models of infection,” was supported by the Mathematical Biosciences Institute, the National Science Foundation (grant numbers DMS-1440386, DMS-1853587 and DMS-1764421) and the Simons Foundation (grant number 597491-RWC). The students’ research has been supported by Northwestern’s Office of Undergraduate Research and NSF DMS-1547394.

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November 1, 2020 10:19 am

What would this model say about the Clinton disease?

Bryan A
Reply to  ResourceGuy
November 1, 2020 3:30 pm

It says that potential election result projections are going viral

November 1, 2020 10:23 am

Sounds familiar.

Reply to  Scissor
November 1, 2020 11:35 am

Thanks 🙂

Reply to  Scissor
November 2, 2020 7:17 am

Read up on a simple ‘wire snare’ used to catch small animals such as rabbits, groundhogs, fox, etc. It’s simply a small wire loop that slides closed when pulled. The key for trapping is to position your quarry to place their foot in it. Could be easily done in a flower bed or with sticks or a few bricks/landscape blocks. Just set the loop about 8″ or so above the ground and attach the anchor end to a series of bricks (with holes) and run the wire lead across the bottom of the sign so that when the sign is pulled up the loop catches their foot. They can still run away but will be dragging a couple of bricks/weights. Someone who doesn’t know the simple release procedure will be in a total panic!

Please post video!

November 1, 2020 10:40 am

The “science” of polling is like that of climate change. It’s about messaging that is designed to get people to support a certain position and is not necessarily reflective of reality. For example, MSM polls have Biden ahead in Iowa but have the race tightening. Last minute tightening is indicative of attempts by MSM to maintain some credibility.

The Trafalgar Group has Trump up in Iowa as does “on the ground” the Demoines Register.

This pattern of malfeasance by MSM polling is repeated elsewhere.

Reply to  Scissor
November 1, 2020 11:21 am

use polling data …..

until the left stops scaring the crap out of the independents and conservatives….they are never going to poll

November 1, 2020 10:41 am

Well I doubt they can do any worse than the public polls and exit polls. Double digit leads for Biden disappearing everywhere.

Reply to  rah
November 1, 2020 11:44 am

I just got back from a bike ride in my upper middle class town in Colorado that has been invaded by Californians. Trump signs outnumber Biden signs by a 3:2 ratio. On top of that, many are flying the Stars and Stripes, which is a “secret” Trump sign for many people. Enthusiasm for Hillary was much higher as four years ago, in this area at least, and Trump signs tended to be vandalized and stolen then.

Reply to  Scissor
November 2, 2020 6:48 am

” … many are flying the Stars and Stripes, which is a “secret” Trump sign for many people. …”

I’m seeing that too.

Mumbles McGuirck
Reply to  rah
November 1, 2020 2:08 pm

“former Vice President Joe Biden could attend a campaign event that influences undecided voters.”

Probably influences them to vote for Trump. Biden may be his own worst campaigner. The more he gets out of the basement, the smaller his lead is.

Reply to  Mumbles McGuirck
November 1, 2020 3:18 pm

All dozen that show up!

Joel O'Bryan
November 1, 2020 10:49 am

Common Cultural superstitions:

– Step on a crack, break your mother’s back.
– Break a mirror, 7 years bad luck.
– Don’t walk under a ladder.
– Black cat crosses your path in front of you, turn around – don’t keep going straight.
– Climate change is now unnatural.
– Paying billions of dollars to the UN Climate Fund will fix climate change.
– Destroying our economy will fix climate change.
– Socialism will fix climate change.
New one:
– Viral epidemic models can also predict human election outcomes.

I know there are lots more, this is just a short list.

Reply to  Joel O'Bryan
November 1, 2020 1:35 pm

– Don’t walk under a ladder.

…….. especially if the guy above is painting ! 🙂

Reply to  Joel O'Bryan
November 1, 2020 1:45 pm

Interesting list. I think there may be something to this comparison of virus behavior compared to human behavior. After all, all those horny little viruses fly around infecting as many people as they can find. Kind of like people.

Reply to  Joel O'Bryan
November 2, 2020 6:45 am

Viral epidemic models can accurately predict viral epidemics?

November 1, 2020 10:50 am

So, what they are saying, is that they don’t know how many people are immune to social contagion, and cannot credibly predict the outcome of a diverse — individual, not color — event.

November 1, 2020 10:59 am

“Experts like the team at Five Thirty-eight….. ”

The ones that had Felonia von Pantsuit up by 98% 24 hours before the ’16 election?

’nuff said.

November 1, 2020 11:13 am

why has this blog veered from climate change denial to Covid and elections? Have you given up on climate? Are the hidden funders admitting defeat and turning to other ways to maintain their wealth?

I miss the climate denial stuff (in part because it has gotten so “up is now down, pass it on” absurdity :-))

Reply to  chris
November 1, 2020 11:34 am

The deniers are those who pretend natural variability doesn’t exist.

Q: Why does climate alarmism persist? A: The left uses it as a vehicle to forward its agenda. We’re seeing the same thing with this pandemic. Everybody and her dog is trying to use the crisis to push an agenda.

All of this is not a victimless crime. The victim is the credibility of science. As WUWT has documented, medical science and climate science are achieving third world levels of corruption. Global warming won’t destroy civilisation but corruption might.

Bruce Cobb
Reply to  chris
November 1, 2020 11:51 am

You must be thinking of some True Believer blog. They deny all sorts of things about climate, CO2, and energy, and always get things completely backwards. But you knew that, right? Now run along like a good little troll. Off you go.

Reply to  chris
November 1, 2020 12:01 pm

Don’t you believe in choice? Climate change is Her, not her, choice.

Reply to  chris
November 1, 2020 12:31 pm

Tell us what we “deny” that you have hard scientific evidence for ?

Accusing people of denying a fairy-tale.. or that the moon is made of cheese…

……. is PRETTY DUMB, when you have absolutely nothing to back up your claims.

1… Do you have any empirical scientific evidence for warming by atmospheric CO2?

2… In what ways has the global climate changed in the last 50 years , that can be scientifically proven to be of human causation?

Or are you just another low-intelligence, gullible muppet with Big Al Gore’s hand stuck up ……….

Reply to  chris
November 1, 2020 12:53 pm

The same people who are saying climate change is bad and it is all our fault are the same people saying COVID-19 is the deadliest virus ever. The solution to these issues is always — ALWAYS — less freedom, the destruction of capitalism, and the UN on top. These people are in cahoots. Joe Biden campaign slogan “build back better” was actually invented by the UN in 2015. (Source: ) Not a coincidence. It has never been about the environment; that is just a red herring. It has never been about saving lives; that is just a red herring. It is always about more power to a select number of elites.

Trying to Play Nice
Reply to  chris
November 1, 2020 3:33 pm

Possibly because there is a “pandemic” that has as much BS spouted by the left as climate change, and because there is a big election on Tuesday? Just guessin’.

November 1, 2020 11:20 am

As of today (Oct. 29), the model forecasts a victory for Biden 89.03% of the time …

Expert predictions, even computer aided expert predictions, are no more accurate than those generated by a dart-throwing chimp.

There should be a punishment for failed prognosticators.

Ed Zuiderwijk
Reply to  commieBob
November 1, 2020 11:45 am

Notice the 0.03%. Must be really accurate.

Reply to  Ed Zuiderwijk
November 2, 2020 6:15 am

” the model forecasts a victory for Biden 89.03% of the time, and a victory for President Donald Trump 10.78% of the time.” = 99.81%

WHOOPS! 2% didn’t answer the questionnaire correctly. The cumulative error over 50 iterations is 100%.

We’ve probably had well over 100,000 polls, based on the number of polling calls I’ve gotten. That means, as a whole, nobody knows who will win the election.

Fancy that. All that money for ignorance.

November 1, 2020 11:23 am

Reporting on polls by media is about views and clicks. The idea is to have a drama so folks will watch on election night. The earlier poll reporting was about supporting the narrative for their fellow travelers to view. It’s about the ads you see.

Kevin kilty
November 1, 2020 11:31 am

Well, left-wing politics looks quite a lot like a disease — an educationally transmitted disease (ETD).

Reply to  Kevin kilty
November 1, 2020 12:38 pm

November 1, 2020 11:45 am

What will see from the MSM until the election is officially decided?

Pearl clutching and straw grasping. It has actually already begun.

Bruce Cobb
November 1, 2020 12:00 pm

What a coincidence, I view Climate Belief as not unlike a nasty virus.

Carlo, Monte
November 1, 2020 12:03 pm

Garbage in—Garbage out

Martin C
November 1, 2020 12:12 pm

Anthony/Mods, the ”jump to another website’ crap is coming back again; only for me it was saying flash player needs to be loaded (rather than virus software being out of date like last time . . ).
Reading this post, as i got down to the comments, it ‘jumped’ to this website:

Not sure if one of the ads or something has this embedded in it, but something is causing it.

Reply to  Martin C
November 1, 2020 6:22 pm

Just a guess, but this sounds like adware on your computer (probably not anything to do with this site). Not sure what the latest anti-adware programs are; I use Avira’s free antivirus, and they also provide a free anti-adware:

BUT, you should not trust me, just because I happen to have posted on this site. Do a web search for “adware removal”, and then go to a site you trust. I think google, bing, yahoo, and duckduckgo will all prevent bogus sites–sites that would install malware–from coming up. But they also tend to put ads for paid versions up at the top, so you may need to scroll down a ways, or go to one of the reviews of adware, which will tell you which ones are free.

If otoh it is some ad on this site, then you might want to install an ad blocker plugin in your browser. Your browser should recommend a safe ad blocker.

Martin C
Reply to  mcswell
November 1, 2020 8:47 pm

Thanks mcswell; but fyi i have not had this happen on any other sites i visit except WUWT. And a NUMBER of people had this happening a few weeks ( i think) ago.

If this were to continue, no doubt i will look into adware removal. And i do have ad blockers; but one issue i have found is that some sites (decent sites by the way) are now ‘detecting’ them, and then not loading the page selected; so a decision to when to activate them . . .

Reply to  Martin C
November 2, 2020 6:52 am

Yes, I was having this problem a couple weeks back. Haven’t noticed it this time around, but it’s almost certainly sneaking in via the ads.

Reply to  mcswell
November 2, 2020 12:20 am

Then I had the same adware yesterday. And it only happens here.

November 1, 2020 12:16 pm

These “mathematical models” are programmed to produce the output the model’s designers want to see. There’s no magic.

November 1, 2020 1:55 pm

Don’t tell me, they run the model many times and take the average – it’s standard procedure these days.

November 1, 2020 3:56 pm

Carnac The Magnificent was better than any of those original post individuals at divining. With his bejewelled turban & embroidered cape Carnac regularly graced the Johnny Carson Tonight Show TV program back in the 1960s. Legend has it that he merely had to hold a sealed envelope containing any kind of question up to his head & then, without fail, could pronounce the correct answer.

November 1, 2020 5:33 pm

LOL! After weeks of declaring Bidden will win, with his only equivocation being that Trump may cheat; Nate Silver is back peddling. Such a slimy little worm.

Tom Abbott
November 1, 2020 5:56 pm

After Trump trounces Biden, all the pollsters ought to resign.

Reply to  Tom Abbott
November 1, 2020 11:53 pm

Learn to code.
Yesterday across this land the Trump Train rolled. From Beverly Hills to NJ, NY, and even South Philly!
The people are singing and making their message loud and clear.

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