Future Index

Methodology

Where the Forecast Movement figure comes from

How much the probabilities on the forecast questions this product tracks have changed over the last day, measured as how many of them moved and how far.

How it is put together

  1. The questions

    Prediction markets and forecasting platforms each publish a probability for the questions they list. This product reads each source separately, and a question here is one source's own contract — two sources asking something similar are never merged into a single question.

    In full: Probability

    If this produces nothingA source that stops answering takes its own questions out of the figure, and how many questions were behind it is published beside it. Nothing is carried forward at its last known probability.

  2. The readings

    Each question is polled on a schedule set by what its source permits, and every reading is stored with the instant it was taken. Readings are never overwritten, which is what lets a figure published today be recomputed later from exactly what produced it.

    In full: Freshness

    If this produces nothingA poll that fails leaves the previous reading in place and moves the figure's freshness state, rather than a gap being filled in with an assumption.

  3. How far each question moved

    For each question, the change over the window is measured against that question's own earlier reading.

    In full: Change over time

    If this produces nothingA question with no reading from a window ago has no change, and is left out and counted rather than treated as having stood still.

  4. What an ordinary move is for that question

    How much a question normally moves in a day is estimated from its own recent readings, so a move can be judged as large or small for that question rather than against every other question on the site.

    In full: Variability

    If this produces nothingA question with too little history to say what an ordinary move looks like is left out and counted, never given a stand-in figure borrowed from elsewhere.

  5. This figure

    What is left is combined in equal parts: how many questions moved beyond the threshold, and how far the average one moved, weighted by how well supported each question's number is. Both halves are published as well as the blend.

    In full: Outlook — how much expectations are moving

    If this produces nothingIf nothing survives the exclusions above, the figure is not published at all. The hero says which of the four is missing and why, and never shows an empty measurement as a low one.

Outlook — how much expectations are moving

Each question is judged against itself. A question's own recent history says how much it normally moves in a day; the movement over the last day is measured in multiples of that, so five points of probability counts as a large move on a question that usually barely shifts and an ordinary one on a question that swings routinely.

Two halves are then combined in equal parts. The first is how many questions moved beyond the threshold below — the breadth of the change. The second is how far the average question moved, weighted by how well supported each question's number is, on a scale that flattens at the top so that one dramatic question cannot decide the figure alone. Both halves are published separately as well as blended.

A question with no reading from a day ago, or with too little history to say what an ordinary move is for it, is left out and counted. The count is published, because a figure taken over eight questions out of four hundred is a different statement from the same figure over all four hundred.

What this does not say

Numbers this uses 5 constants
Constants used by Outlook — how much expectations are moving, with their units and how each was arrived at
ValueWhat it doesHow it was arrived at
2 multiples of a question's own normal daily move
outlook.significanceRatio
How far a question has to move, compared with how much it usually moves in a day, before it is counted as having moved at all.A reasoned choice with no observed distribution behind it yet. Read it as a stated position, not a measurement.
0.01 percentage points of probability
outlook.minTypicalChange
The smallest daily movement any question is treated as normally having. It stops a question that has barely traded from reporting a huge departure on a single small change.A reasoned choice with no observed distribution behind it yet. Read it as a stated position, not a measurement.
3 multiples of a question's own normal daily move
outlook.magnitudeReference
The average departure at which the size half of this figure reaches the top of its scale.A reasoned choice with no observed distribution behind it yet. Read it as a stated position, not a measurement.
0.5 share of the figure
outlook.breadthWeight
How much *how many* questions moved counts toward the figure.A reasoned choice with no observed distribution behind it yet. Read it as a stated position, not a measurement.
0.5 share of the figure
outlook.magnitudeWeight
How much *how far* they moved counts toward the figure.A reasoned choice with no observed distribution behind it yet. Read it as a stated position, not a measurement.

What this product does not claim

Stated positions about what this figure is, not a list of things not built yet.

Outlook says how much expectations moved, never whether they improved

The outlook figure has no direction in it. It is not higher when forecasters grow optimistic and lower when they grow pessimistic; it is higher when the numbers move and lower when they sit still, whichever way they went.

The whole position

Forecasts are not combined across sources

Future Index does not currently combine forecasts from different sources into a single number. Each question shown is one source's contract, and every figure on it is computed from that source alone.

The whole position

Every threshold on this page is stated, not measured

All the numbers here are stated defaults: reasoned choices with an argument behind each and no observed distribution to place them against. That is stronger than it sounds — it means none of them was fitted to anything, not even second-hand.

The whole position

The rest of it