Today’s newsletter was originally conceived of as something slightly different, a sort of very meta column about FLIPR vs. prediction markets.
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newsletter → conceive → markets
But I’m feeling a little meta-d out this weekend — maybe it was seeing You Can See Everything on Friday.1
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You → feel → Everything
And I realized I had a lot of spare thoughts about individual Senate races, including some we haven’t discussed much at Silver Bulletin.
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we → realize → Bulletin
So let’s keep this more tangible and I’ll go race-by-race through the map.
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I → let → map
The headline calls this “shop talk,” but what it absolutely isn’t is any sort of insider speculation.
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is → call → speculation
That’s not my thing.
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That → ’ → ?
Rather, it’s how I’d speak to a friend who knows the territory, where we share enough assumptions in common that I can be slightly unguarded.
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I → ’ → assumptions
I do this a lot on Still Counting or in external media appearances, but it’s also squarely within the territory of Model Talk.
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it → do → Talk
Because, yes, I have thoughts and intuitions beyond what’s reflected in FLIPR.
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what → have → FLIPR
My jumping-off point for these questions are races where we differ from other models, prediction markets, or the conventional wisdom.
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we → jump → models
What are they seeing that I’m missing, or vice versa?
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I → see → that
Are there other reasonable modeling choices I might have made that would have produced a meaningfully different forecast?
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that → make → forecast
I guess that’s a way of saying “where do I trust FLIPR and where don’t I?” although I don’t think that’s quite the right framing.
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that → guess → FLIPR
For one thing, I mostly do trust FLIPR.
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I → trust → FLIPR
For another, the whole point of building a model, in some sense, is to set clear rules ahead of time so you don’t have to trust your gut or make ad hoc assumptions in midstream.
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you → build → midstream
Now that we’re in “silly season,” it sometimes feels like everyone from the expert ratings agencies to the pollsters themselves are hedging their bets or sometimes herding.
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everyone → ’re → bets
FLIPR might be wrong, but it gives you an independent opinion every day, based on rules we locked into place months ago.
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we → give → place
Still, I keep a mental list each cycle of things we might change in our models the next time around.
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we → keep → models
I promise: we’ll get into the individual Senate races shortly.
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we → promise → races
But for context, let’s quickly look at the topline numbers.
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’s → let → numbers
Models and markets have converged, but FLIPR remains a bit more confident in Democrats’ Senate chances
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FLIPR → converge → chances
It would take a polling error of epic proportions — bigger than in 2016 — for Democrats to fail to pick up the chamber.
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Democrats → take → chamber
Statistically, it’s possible, but you’d start to get into the fat-tailed ends of the distribution where both the polls and a lot of the assumptions we’ve been making about politics, including decades-old trends about weak performance for the president’s party in midterms, are deeply wrong.
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we → ’ → midterms
I wouldn’t call it a major disagreement, and the gap has closed some in recent days, but it’s also more than a “rounding error’s” worth.
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it → call → worth
Polymarket2 gives Democrats a 2-in-3 chance of winning the Senate, whereas FLIPR puts it at 3-in-4.
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FLIPR → give → 3
FLIPR launched on Aug. 11, but I’ve run the Polymarket data series back to Aug. 1.
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I → launch → Aug.
In the markets, there was a reasonably big jump in Democrats’ odds on Aug. 11; I don’t remember that having been an especially good day of news or polls for Democrats, so that could plausibly have been markets reacting to FLIPR itself.
FLIPR and Polymarket then moved basically in tandem with one another through roughly Sept. 22, with both seeing a sharp increase in Democrats’ win probability shortly after Labor Day.
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both → be → Day
(Though if you squint, I think you can say that FLIPR led the markets by a couple of days.)
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FLIPR → squint → days
Then our forecast continued to improve for Democrats while their market rally stalled out.
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rally → continue → Democrats
But now our forecast has been very flat for the past two weeks — there’s actually been just the slightest downtick for Democrats over the past couple updates — while Polymarket has shifted toward Democrats over the past few days instead.
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Polymarket → shift → days
The Aporia
