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How the Futur model works

Futur is a game, but the economy underneath it is a real, published, tested model. This page shows what it does, where its numbers come from, how it was checked, and where it is weak.

It is a stylised model of the UK economy from 2025 to 2035. It is a thinking tool, not a forecast. It is more reliable at showing the difference AI makes (your Britain against the same world without AI) than at predicting any single number.

1. What the model does each year

  1. AI spreads. Adoption follows an S-curve. It speeds up when AI is cheap compared with the pay of the workers it could replace. The cost of AI halves every four years by default.
  2. AI adds to productivity. How much depends on the hidden world you are playing in (section 4).
  3. Gains tilt towards capital. As machines do more, owners of capital take a larger share of income. A tax on capital pulls that back.
  4. Three groups of workers feel it differently. Junior workers (about 24% of the workforce) are the most exposed, mid-career workers (about 56%) are mixed, and senior workers (about 21%) gain the most from working alongside AI. The shock to each group is split between lost jobs and lower pay according to how flexible that group is.
  5. The books must balance. Total pay is always forced to equal the labour share of the economy, so the model cannot invent money.
  6. Inequality moves. It rises with a slow background drift, with machines taking over more income, with a widening pay gap between senior and junior workers, and with youth unemployment. A basic income compresses it a little.
  7. The public finances update. Revenue and spending start at 40.5% of the economy. A basic income, a capital tax and AI profits change them. Debt grows with interest.
  8. Stability is scored. It combines inequality, unemployment, youth unemployment, the pay share, years of flat wages, and wealth concentration.

The crisis lines that end a game early are: debt above 130% of the economy, youth unemployment above 12%, the pay share below 55%, or stability below 0.55.

Starting point (2025): economy £2,750bn, pay share 59.5%, debt 95% of the economy, richest 10% hold 43% of wealth, inequality (Gini) 0.329.

2. Where the numbers come from

Part of the modelBased on
Baseline growth, population and public financesOffice for Budget Responsibility (OBR) November 2025 forecast; ONS 2024 income inequality; ONS Labour Force Survey April 2026; OECD Economic Outlook 2025/2
The three worker groups and how flexible each isStanford / ADP evidence on entry-level work; Brynjolfsson and Li (QJE 2025); Bloom and Prettner on the skill premium; Hamermesh (1993) on labour demand; Manning (2021) on elasticities
Productivity, capital share and adoptionAcemoglu (2024) on productivity; IMF Working Paper 2025/068 on capital share; the Acemoglu-Restrepo task framework for adoption; Turchin for the stability idea

Checks made on figures people often quote

When this project was reviewed in October 2026, several widely repeated figures were checked against the primary source. What was found:

A second review of a separate research library (October 2026) supported several of the settings, notably that young people's job-finding has fallen in AI-exposed work while overall unemployment has not yet risen, and that firms' own reports of AI productivity gains are much higher than measured gains so far.

3. How it was tested: the backtest

The model was run on the UK for 2015 to 2019, a period before today's AI, and compared with what actually happened.

MeasureAverage miss, first version (v4)Average miss, current calibrated engine (v5)
Size of the economy3.9 percentage points0.5 percentage points
Inequality (Gini)0.0290.009
Unemployment0.85 percentage points0.5 percentage points

Three fixes closed the gap: a small steady background rise in inequality (housing wealth and top incomes), faster recovery of unemployment after a shock (matching how quickly UK unemployment actually adjusted), and a correction to how labour enters the production function.

What the backtest does and does not show. It shows the model reproduces the UK's ordinary behaviour in a normal period. It cannot show that the AI effects are right, because there was no AI shock in 2015 to 2019 to test against. The AI settings rest on the published research above and on the range of views in section 4.

The game adds extra mechanisms on top of the tested engine: a hiring freeze for young workers, new tasks created by AI, capital moving abroad when capital tax is high, higher borrowing costs when debt is high, and a social-tension score. These are stylised and not calibrated to measured data, because no source gives the sizes. They were tuned so that no single policy always wins. The backtest does not cover them.

3b. The game on top of the model

The game adds a few things to the tested engine. They are stylised choices, not measured effects:

One known weakness: in the model a faster rollout is almost never worse than a slower one, because scores are judged in 2035, after any transition cost has passed. This is recorded as an open calibration question.

4. The hidden worlds

You never know how much productivity AI will really deliver. Each game secretly picks one of four worlds:

WorldExtra productivity growth a yearAnchored on
Sceptic0.1 to 0.3%Acemoglu-style low estimates; measured studies so far find close to no effect on pay or hours
Steady0.6 to 0.9%Task-based mid estimates; in line with OECD estimates of 0.4 to 1.2% for the UK
Boom1.0 to 1.5%Historical-analogy estimates; the OBR's 1.5% upside case
Surge1.5 to 2.0%Upper estimates in the style of investment-bank scenarios

The ranges are modelling choices that span the published debate. They are not predictions about which world is likely.

5. What the model leaves out

The unrest score is a rough indicator, not a measured quantity.

6. See for yourself

Every game can be replayed exactly: the same hidden world and the same choices give the same result. The model has an automated test suite, including a check that the original calibrated results are reproduced exactly, and every change to the engine is documented with what it affects.

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