Methodology
Every weight, every input, every transformation. Copy this page to your own spreadsheet and reconcile the numbers — that is the whole point.
How the score is built
- Collect. Each indicator is pulled from a named public source on a defined cadence (see the table per pillar).
- Normalise. We compute a z-score for each indicator against a rolling baseline starting
2019-01-01, excluding the COVID shock window2020-04-01–2020-06-30. - Direct. Where a rising raw value is good (e.g. real pay, FTSE 250), we flip the sign before normalisation.
- Bound to [0, 100]. We pass the z-score through an empirical cumulative distribution function (ECDF) over the same baseline. The chart below illustrates the mapping: a z of +2 maps to roughly 98, a z of 0 maps to 50.
- Pillar score. Weighted arithmetic mean of the pillar's indicators. Arithmetic at the pillar level means individual inputs are additive and debuggable.
- Headline Tightrope Score. Weighted geometric mean of the four pillar scores. Geometric at the headline level means one pillar blowing out (e.g. a gilt shock) pulls the headline hard — the correct behaviour for a systemic-stress metric.
ECDF — the z → [0, 100] mapping
Percentile of standard-normal CDF on the y-axis, z-score on the x-axis. We use the empirical (not normal) CDF in production — this figure is illustrative.
Inputs, weights and sources by pillar
Market Pressure 40% of headline
Are markets tightening the vice? — cadence intraday.
| Indicator | Weight | Unit | Direction | Source |
|---|---|---|---|---|
| 10-year gilt yield UK 10-year benchmark gilt yield (daily close). | 15% | % | Rising = worse | Bank of England -- Statistical Database (gilt yields) ↗ |
| 30-year gilt yield UK 30-year gilt yield. Sensitivity proxy for long-duration borrowing. | 13% | % | Rising = worse | Bank of England -- Statistical Database (gilt yields) ↗ |
| GBP / USD Sterling vs. US dollar. | 6% | ccy | Rising = better | Bank of England -- Exchange rates ↗ |
| GBP trade-weighted index Broad effective exchange rate index for sterling. | 6% | index | Rising = better | Bank of England -- Exchange rates ↗ |
| SONIA 12-month forward 12-month SONIA forward -- market-implied short-rate path. | 8% | % | Rising = worse | Bank of England -- SONIA ↗ |
| UK natural gas front-month Front-month NBP natural gas settlement price. | 8% | p/th | Rising = worse | ICE -- UK Natural Gas Futures ↗ |
| FTSE 250 Mid-cap index -- cleaner domestic UK read than FTSE 100. | 8% | index | Rising = better | LSEG -- FTSE 250 ↗ |
| 5y breakeven inflation 5y nominal minus 5y real gilt yield -- market-implied CPI/RPI 5y ahead, a direct proxy for OBR's CPI inflation path over the forecast horizon. | 8% | % | Rising = worse | Bank of England -- Statistical Database (gilt yields) ↗ |
| 10y breakeven inflation 10y nominal minus 10y real gilt yield -- proxy for longer-horizon inflation expectations feeding OBR's medium-term CPI and debt-interest forecast. | 6% | % | Rising = worse | Bank of England -- Statistical Database (gilt yields) ↗ |
| 10y real (IL) gilt yield 10y index-linked gilt real yield -- proxy for the real rate regime that OBR uses when deriving potential-output and trend-growth assumptions. | 4% | % | Rising = worse | Bank of England -- Statistical Database (gilt yields) ↗ |
| Brent crude in GBP Brent dated spot price converted to GBP -- the single largest swing input to OBR's CPI energy subcomponent and fuel-duty receipts. | 5% | GBP/bbl | Rising = worse | US EIA -- Europe Brent Spot Price (FOB) ↗ |
| UK housebuilder composite Equal-weighted price index of the five largest listed UK housebuilders (rebased 100 = 2019 avg) -- leads OBR's residential investment and construction GVA lines by 3-6 months. | 5% | index | Rising = better | LSEG -- UK listed housebuilders (composite) ↗ |
| S&P Global UK Services PMI Headline Services PMI -- 50 = no change. Services is ~80% of UK GVA, so this leads OBR's real-GDP growth forecast by roughly one quarter. | 4% | index | Rising = better | S&P Global -- UK Services PMI ↗ |
| GfK consumer confidence GfK/NIESR consumer confidence headline index -- leading signal for household-consumption growth, the largest single expenditure line in OBR's GDP decomposition. | 2% | index | Rising = better | GfK / NIESR -- Consumer Confidence Barometer ↗ |
| RICS house-price balance Net balance of RICS surveyors reporting price rises vs. falls -- leads residential investment in OBR's expenditure GDP by 1-2 quarters. | 2% | % | Rising = better | RICS -- UK Residential Market Survey ↗ |
Fiscal Constraint 30% of headline
Is the fiscal buffer shrinking or expanding? — cadence event.
| Indicator | Weight | Unit | Direction | Source |
|---|---|---|---|---|
| Current-budget headroom Surplus against the stability rule at the target year. | 35% | GBPbn | Rising = better | Office for Budget Responsibility -- Economic & Fiscal Outlook ↗ |
| PSNFL trajectory deviation Deviation of PSNFL path from OBR baseline, percentage points of GDP. | 15% | pp | Rising = worse | Office for Budget Responsibility -- Economic & Fiscal Outlook ↗ |
| Borrowing outturn vs. OBR path Year-to-date public-sector net borrowing, gap vs. OBR profile. | 15% | GBPbn | Rising = worse | ONS -- Public Sector Finances ↗ |
| Debt interest vs. forecast Rolling 12m debt-interest bill vs. OBR forecast. | 15% | GBPbn | Rising = worse | ONS -- Public Sector Finances ↗ |
| Index-linked gilt share of stock Share of outstanding gilt stock that is index-linked -- inflation-sensitivity proxy. | 10% | % | Rising = worse | UK Debt Management Office ↗ |
| Long-conventional issuance share Share of planned annual issuance classed as long conventional. | 10% | % | Rising = worse | UK Debt Management Office ↗ |
Labour & Living-Standards Strain 20% of headline
Is the labour force getting healthier and more engaged? — cadence monthly.
| Indicator | Weight | Unit | Direction | Source |
|---|---|---|---|---|
| Economic inactivity rate, 16-64 Share of 16-64 population neither in work nor looking for work. | 22% | % | Rising = worse | ONS -- Labour Market Statistics ↗ |
| Health-related inactivity (m) Millions reporting long-term sickness as main reason for inactivity. | 18% | m | Rising = worse | ONS -- Labour Market Statistics ↗ |
| Unemployment rate, 16+ ILO unemployment rate. | 10% | % | Rising = worse | ONS -- Labour Market Statistics ↗ |
| Vacancies per unemployed person Tightness of the labour market; falling = slack. | 10% | ratio | Rising = better | ONS -- Labour Market Statistics ↗ |
| PAYE payroll employees (MoM) Month-on-month change in PAYE payroll count. | 10% | pp | Rising = better | ONS -- Real-Time Indicators ↗ |
| Real regular pay growth, YoY CPIH-adjusted regular pay, year-on-year. | 10% | % | Rising = better | ONS -- Labour Market Statistics ↗ |
| Average 2y fixed mortgage rate UK average 2-year fixed-rate mortgage at 75% LTV. | 12% | % | Rising = worse | Moneyfacts -- UK Mortgage Rates ↗ |
| Direct-debit failure rate ONS real-time indicators -- share of direct debits failing. | 8% | % | Rising = worse | ONS -- Real-Time Indicators ↗ |
Growth Delivery 10% of headline
Are the promised growth reforms visibly delivering? — cadence event · inverted (higher raw delivery = lower pressure).
| Indicator | Weight | Unit | Direction | Source |
|---|---|---|---|---|
| Net housing additions vs. trajectory Latest net additions as % of OBR trajectory for the year. | 25% | % | Rising = better | MHCLG / DLUHC -- Housing Statistics ↗ |
| Planning consents vs. baseline Residential planning consents vs. 2019 baseline. | 20% | % | Rising = better | MHCLG / DLUHC -- Housing Statistics ↗ |
| New towns milestones hit Milestones hit as % of committed milestones YTD. | 15% | % | Rising = better | gov.uk -- Announcements RSS ↗ |
| BICS firms onboarded Cumulative firms onboarded to the British Industrial Competitiveness Scheme. | 15% | firms | Rising = better | Department for Energy Security and Net Zero ↗ |
| Industrial Strategy milestones Industrial Strategy milestones on/ahead of schedule vs. slipped/missed. | 15% | % | Rising = better | Department for Business and Trade ↗ |
| SMR fleet progress Small Modular Reactor programme progress against published milestones. | 10% | % | Rising = better | gov.uk -- Announcements RSS ↗ |
Last successful ingestion per source
| Source | Last run | Status |
|---|---|---|
| seed | 17 Apr 2026 | success |
Open questions & known limitations
- The baseline window excludes 2020 Q2 but retains the 2021–22 energy shock period. Changing the baseline requires a versioned methodology update — no silent rebaselining.
- Intra-pillar weights sum to 1 per pillar; they are normalised at scoring time even if the raw
weightvalues inINDICATORSdon't sum to exactly 1 (they are target weights). - Delivery is inverted: we flip the raw progress reading before combining with the other pillars so that every pillar score reads "higher = more pressure".
- The geometric mean at the headline level cannot handle a zero input. In practice no pillar score reaches 0 — if it did, we would floor it at 1 for aggregation and publish the floor.
Corrections, source code, snapshots
Every correction to a published number appears in the corrections log, dated, with the original and revised values and the reason. The source code for the scoring library is MIT-licensed on GitHub, and the nightly snapshot of the D1 database is committed publicly — if you believe a number on this site is wrong, you can verify it end-to-end.