[HN Gopher] How The Economist's presidential forecast works
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How The Economist's presidential forecast works
Author : tosh
Score : 73 points
Date : 2024-06-16 18:05 UTC (4 hours ago)
(HTM) web link (www.economist.com)
(TXT) w3m dump (www.economist.com)
| jkic47 wrote:
| Pretty cool site reminiscent of the 538 analysis of elections
| past. I wonder how the model will react if Biden drops out before
| the election, though, since the blue polls would suddenly be
| "obsoleted" (wrong word, I know) with a new incumbent.
| seanmcdirmid wrote:
| It is too late for Biden to bow out. Although the chance of
| either Biden or Trump dying before the election is
| uncomfortably high.
| plonk wrote:
| They're both supposed to be in good health though, we have
| Biden's public yearly checkup report. I don't think many old
| people get scans and full-body checkups every year and then
| die of something catastrophic with no warning?
| refulgentis wrote:
| My priors would go the opposite way: a full-body checkup
| cannot clear out the plaque in my arteries, lower my blood
| pressure, strength my vascular walls, and there's no
| miracle drugs that definitively address those. I think of a
| checkup that says "good to go, won't die in the next year!"
| is more like an auto checkup, where we do diagnostics then
| can take definitive action.
|
| That being said saying odds are one of them dies before the
| election is uncomfortably high isn't something I'd
| subscribe to. Quick check here, using N=age-google-told-me
| and N+1, gets 1 in 18 and 1 in 13, 6% and 8%. If they were
| 60 it'd be 1%, 70, 2%.
|
| https://www.candidmoney.com/calculators/death-probability-
| ca...
| spywaregorilla wrote:
| Actuarial tables tell you basically nothing about a
| specific individual. For that you would want to look at
| some personal. Like, say, a full body checkup.
| refulgentis wrote:
| Yeah thats a good point, I agree, a full body checkup
| tells us stuff about an individual, but it doesn't heal
| them (or at length: meaningfully rule out, or affect,
| odds of dying in the next year)
| plonk wrote:
| Apparently [1], Biden at least has "controlled"
| cholesterol, a normal EKG, some asymptomatic and
| controlled fibrillation. The number of experts who
| consult the guy every year is actually impressive.
|
| The usual 70-year-old is probably a risky bet, but surely
| 10 specialists plus a team of generalists would make a
| more predictive yearly checkup. I think he's going to
| lose through normal politics and not by way of a heart
| attack.
|
| [1] https://www.whitehouse.gov/wp-
| content/uploads/2024/02/Health...
| mikeodds wrote:
| I didn't realise his checkup was public [1]
|
| I thought there would be more around neuro in there.
| Interesting that both recent presidents are (purportedly)
| non drinkers.
|
| [1] https://www.whitehouse.gov/wp-
| content/uploads/2024/02/Health...
| ta1243 wrote:
| Bush II was tee-total too wasn't he?
| pyuser583 wrote:
| Not an expert, but my experience is old people can decline
| very fast.
|
| It's literally the best possible outcome of old age: being
| energetic and in full capacity, declining quickly and
| passing on.
|
| The alternatives are dying early, or a long period of
| dependency.
|
| But yeah, that's how old people die.
| okaram wrote:
| Still, their actuarial chance of dying within a year is
| >5%, given their age and sex.
|
| Even with scans and checkups, at that age, a bad case of
| the flu can kill you, or start you on that path. And I
| don't think we have any reliable non-invasive ways of
| detecting heart attack risk, or aneurism risk, those kinds
| of things.
| TeaBrain wrote:
| We haven't had an election like it in over 50 years, but in
| 1968 the democratic candidate was Hubert Humphrey, who
| entered the race too late to participate in any primaries.
| QuesnayJr wrote:
| Can't Biden bow out any time before the Democratic National
| Convention in mid-August? I don't expect that he will, but he
| could.
| krapp wrote:
| It would be political suicide for the Democrats not to go
| with a sitting incumbent President as their candidate,
| especially against a candidate who was formerly President.
| TMWNN wrote:
| Correct.
|
| Further, Biden dropping out would cause another civil war
| within the Democratic Party that is already dealing with
| one between the pro-Hamas and pro-Israel sides. Kamala
| Harris is so unpopular that she absolutely cannot win,
| but parachuting in Gavin Newsom, who has his own
| handicaps,[1] would cause Harris's side to cry
| racism/sexism/etc. And this is all setting aside the
| difficulty of whoever is Biden's replacement campaigning
| to become president against someone who has, as you said,
| already done the job for four years. Four years which,
| polls consistently show, more voters look back positively
| upon than not.
|
| [1] The best description I've heard of Newsom is that he
| looks like the mayor of Gotham City.
| Mountain_Skies wrote:
| Different states have different deadlines for getting on
| the ballot. The DNC is already going to have to a pre-
| convention virtual convention where they legally nominate
| Biden so he can get on the ballot in Ohio. The physical
| convention will be for rallying the party behind him. If
| they were to switch to someone else at the convention, at
| the very least Ohio would retain Biden on the ballot. Ohio
| does allow for 'faithless' electors, so Biden winning Ohio
| while the official nominee won other states might not be
| the worst thing provided the electors could be trusted to
| switch their vote to whoever the DNC put up in place of
| Biden.
| ta1243 wrote:
| The chance of them both dying is uncomfortably low.
|
| Seriously, the best two candidates the entire USA has to
| offer are these washed up octagenarian politicians?
| mensetmanusman wrote:
| They are a symptom of a gridlocked and extortionist
| political system that serves the elite.
| mensetmanusman wrote:
| Every year they get older, they have a higher chance of
| surviving until the next year. It's a weird thing about
| aging. Of course until you die that is.
| TheCleric wrote:
| I would bet large amounts of money that Biden doesn't drop out
| before the election. It would be unprecedented and there's no
| indication it would happen.
| twelfthnight wrote:
| I've worked as a data scientist for political campaigns (but no
| longer). The elephant in the room is that there are so many
| forces that make this election different from historical ones,
| from polls moving online away from phones (making them much much
| less reliable) to Trump's conviction to a completely
| unprecedented/fractured media landscape. Even if these forecasts
| were accurate, their usefulness for anyone other than people
| spending ad money is absolutely zero. Now that these forecast
| have so so much bigger error bars, I think public forecasts are
| actually harmful and just a scummy money grab from the media that
| posts them.
|
| EDIT:
|
| Why are they harmful? At best they make lots of people angry
| about something that hasn't happened. At worst they skew the
| election by making people not vote, or afterward serve to justify
| election fraud complaints ("my candidate wasn't supposed to lose
| based on forecasts, so fraud occured").
|
| I think we all need to take a deep breath, accept we have little
| understanding what will happen, _vote_, and hope for a sane
| outcome.
| gautamcgoel wrote:
| It's great to see the Economist explain statistical concepts like
| parsimony, regularization, cross-validation, and MCMC methods in
| a way that is both accessible and completely accurate. I can't
| think of another mainstream publication that would bother to
| explain the mathematical techniques behind their model in such
| detail. Kudos to the Economist!
| twelfthnight wrote:
| This is great statistics, but it avoids the problem that moving
| to online polling has made it very difficult to get
| representative populations, so the data itself is biased in
| ways that cannot be counteracted by methods (only by
| assumptions, priors, etc). Which makes this misleading because
| it gives the forecast air of confidence that is unjustified.
| JumpCrisscross wrote:
| > _makes this misleading because it gives the forecast air of
| confidence_
|
| The entire first half of the article is about why polling is
| not only unreliable at this point, but becoming increasingly
| unreliable in biased ways.
| twelfthnight wrote:
| True, I suppose my disagreement is that I believe it
| doesn't go far enough to explain how big of a deal it is,
| and how there _aren't_ ways to deal with it without
| substantial, subjective intervention from the forecasters.
|
| I've worked on weighting code for online polls, they
| literally rely on dozens of hand picked decisions to stay
| "reasonable". These decisions aren't factored into the
| error bars, making them appear smaller.
|
| And as far as the fundamental style predictions, how can
| you use a single GDP number when Fox tells its viewers one
| number and MSNBC tells its viewers another?
|
| This article does describe a faithful statistical effort,
| but to me it doesn't emphasize the risk of a "black swan"
| event enough.
| whakim wrote:
| Absolutely. But we've been past the "golden age" of
| polling using live callers on landlines for more than 20
| years now. We now have a reasonable corpus of polling
| data that we can use to evaluate how good pollsters are
| at making the corrections (often educated guesses) that
| they use to adjust their polls.
| AlexCoventry wrote:
| The justification for Bayesian inference, that the
| posterior will eventually converge to the true
| distribution, breaks down unless your prior has support for
| a good approximation to the data-generating model. So
| without a good model of how polling results map to actual
| voter distributions, the Economist model is guesswork, to a
| large extent.
| dsugarman wrote:
| https://abcnews.go.com/538/538s-2024-presidential-election-f...
| doctorpangloss wrote:
| This sounds like a more thorough update to the 2020 model they
| published here:
|
| https://github.com/TheEconomist/us-potus-model
|
| Nate Silver was both the best and worst thing that happened to
| these predictions. The modus operandi of people in media (New
| York and Hollywood) is "gut checks" - Dean Baquet is only going
| to publish a model, no matter what the math says, that agrees
| with his "gut" that Clinton was going to win 2016. He was so
| crazy wrong but like, he's not getting fired. Laypeople and
| cranks conflate making a mistake that everyone in media made with
| a conspiracy between Democrats and the media, unable to grasp
| incompetence. Of course, if Dean Baquet had spent five minutes
| talking to a political scientist of some merit, asking, "is the
| voter turnout of traditional demographic groups like women and
| old people is really as predictive of elections as Nate Silver
| said it was?" He would have learned that Australia has had
| compulsory voting for decades and it is as conservative as ever.
|
| Now that "gut checks" have disentangled themselves from New York
| graphics departments - can you believe its the graphics
| department, masquerading as a "data science" department, that
| runs election forecast stories?! - maybe forecasts will be better
| everywhere.
|
| If I were doing this, I'd frame it as a Kaggle competition built
| on PyroPL. And I'd require top performance in democratic election
| forecasting everywhere, not just the US. The Economist is right,
| it's all about fundamentals, but _which_ fundamentals, and can
| you prevent the _choice_ of fundamentals from reflecting the
| publisher 's political aspirations? Personally I'm skeptical that
| the Economist's choice of GDP growth makes any sense, and net
| approval rating sounds like a poll, so... there must be something
| better.
| islewis wrote:
| > Nate Silver was both the best and worst thing that happened
| to these predictions.
|
| Can you elaborate on this opinion further? I have a hard time
| aligning the rest of your post with what looks like your
| thesis.
| rayiner wrote:
| I gotta give the economist credit for acknowledging that Trump
| has a clear lead. https://www.economist.com/united-
| states/2024/06/12/five-mont...
|
| Biden's only realistic shot is to sweep Michigan, Wisconsin and
| Pennsylvania. Biden is polling 4-8 points behind where he was in
| June in those states in 2020, and where Clinton was in 2016.
| jasondigitized wrote:
| As an American so many of my fellow citizens have been duped
| and will now be fleeced.
| rayiner wrote:
| "Duped" how? Say what you want about Trump, but "hiding the
| ball" isn't exactly his thing.
| ceejayoz wrote:
| The man who promised a healthcare plan in "two weeks" for
| about four years straight?
| titanomachy wrote:
| I suppose they do deserve credit, but isn't that degree of
| objectivity the very least we should expect from our news
| sources? I'd be shocked to learn that the economist falsified
| their forecast results.
| TMWNN wrote:
| >Biden is polling 4-8 points behind where he was in June in
| those states in 2020
|
| Further, Trump _consistently_ did better than the polls in
| almost every state in both 2016 and 2020.
|
| To have him actually be up in the polls--something he _never_
| did nationally in the aggregate in 2016 or 2020--is signaling
| landslide.
|
| >and where Clinton was in 2016.
|
| I highly recommend this excellent _Politico_ article on 10 key
| moments of the 2016 election campaign <http://www.politico.com
| /magazine/story/2016/12/2016-presiden...>. One is how Trump
| campaigned like crazy while Clinton took weeks off just loafing
| in Chappaqua.
|
| Eight years later Trump is still campaigning like crazy while
| Biden is hiding in his basement. I was amazed to learn recently
| that Biden as president has _never_ done an interview with a
| major newspaper <https://www.natesilver.net/p/its-time-for-
| the-white-house-to...>; only podcasts like Conan O'Brien's,
| where he knows he'll only get softball questions.
| TheCleric wrote:
| > To have him actually be up in the polls--something he never
| did nationally in the aggregate in 2016 or 2020--is signaling
| landslide.
|
| That's certainly possible, but another explanation is that
| the polls are trying to correct for this and have over
| corrected.
| paulpauper wrote:
| It is going to be very close and decided by key swing states , as
| has typically been the case. It will not be at all like 2008 or
| 2012 or 1996. This is why forecasting models are not that useful
| ,as the swing states are such big and unknown variables. It's
| like "I have 95% confidence that either candidate will get 48-52%
| of popular vote." great, real helpful .
| LudwigNagasena wrote:
| Knowing that a candidate will get 48%-52% of popular vote is
| indeed more helpful than not knowing what's going on at all.
|
| Aleatory, epistemic and ontological uncertainties are three
| different things.
| twelfthnight wrote:
| Honest question, what different decisions could you make with
| a 48-52 interval than a completely uninformed interval of
| 0-100?
| ta1243 wrote:
| You know where to spend your resources.
|
| If you can move the needle in 5 states by a total of 25
| points, you aren't going to waste them in a states where
| it's 60-40.
| e40 wrote:
| Agreed, and the subversion tactics tried before have gone
| through refinement and people put into key positions to make
| 2020 look like a garden party.
| brcmthrowaway wrote:
| looks like trump will win :(
| krapp wrote:
| Honestly, if the US still wants Trump badly enough to vote him
| in, we deserve what we get. Fuck it. At least I'll enjoy
| watching this place burn.
| pessimizer wrote:
| Trump was already president for 4 years.
| krapp wrote:
| Yes, I'm very much aware.
| e40 wrote:
| You mist not be up on the plans for the second season. It's
| not going to resemble his first term hardly at all.
| gedy wrote:
| > still wants Trump badly enough
|
| IMHO it's less about "badly enough", I know very few people
| who are die-hard Trump supporters, but do know many centrist
| types who just aren't very enthusiastic with Biden and Harris
| in the past four years.
|
| The Democrats should really pick someone more desirable for
| the majority of Americans. I know there are decent options,
| even if not the level of exciting as Obama was in 2008.
|
| It's similar to 2016, and many people could not understand
| that much of the Trump vote was basically just not thrilled
| about Hillary Clinton, and was hardly a rally behind Trump.
| ceejayoz wrote:
| I mean, it looked a lot like Hillary would win, too. 538 was an
| outlier in only giving her a 2/3 chance of winning when
| everyone else was saying 90%+.
| jszymborski wrote:
| FWIW, Trump was given worse odds than Hilary much closer to the
| election using the 538 model (which is similar in principle).
|
| Not a knock on these projections, but just a reminder that even
| if a lead is statistically significant, the size of the lead
| matters.
|
| 66% is hardly a fait accompli, especially five months out. That
| said, as Nate Silver has said (paraphrasing), 16% probability
| sounds unlikely until you're playing Russian Roulette.
| softwaredoug wrote:
| At some point the current incarnation of the GOP will have
| power - with or without Trump, 2024 or later. It's just sadly
| something that's going to happen.
| e40 wrote:
| And they've literally told us everything they're going to do.
| That makes watching this all the more painful.
| squidbeak wrote:
| Agreed. Every election it loses in the meantime will amp up
| resentment and aggravate the USA's political dysfunction. I
| think of it as a counterpart of Brexit, which had similar
| populist drivers, and was something the country just had to
| get out of its system, despite the steep attendant economic
| and social costs.
| ta1243 wrote:
| The brexit referendum was supposed to answer the question
| once and for all, and stop the tory party split. Instead we
| have a split down the middle, and the split is far further
| right than it was in the Major/Redwood days of the 90s.
|
| 8 years on we're seeing the tory party massively damaged,
| an outside chance of FPTP meaning they're neither the
| second largest party in seats or in votes. There's a crazy
| situation where half the tory voters are literally voting
| for a company run by Nigel Farage. I suspect 90% of the
| voters would struggle to name anyone else in that company
| (it's not a party the way the tories or greens are).
|
| Brexit didn't solve the problem, there's always something
| else to blame.
|
| One of the most pivotal moments in UK political history was
| Farage surviving the 2010 plane crash. There's just nobody
| else as large on that side of the aisle that can operate
| outside of the party structure (including Johnson)
| plussed_reader wrote:
| Now if the Economist wasn't a warren of conservative talking
| points how might it land?
| galangalalgol wrote:
| I thought the economist was the left one and wsj was the right
| one, relatively speaking?
| kgwgk wrote:
| It seems that they no longer publish an "election day forecast"
| regarding popular vote - something that they included in 2020:
| https://www.researchgate.net/profile/Rachael-Meager/publicat...
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