Eight principles
A family of indices, not one monolithic score
NXS-GRX (canonical data, provenance and risk) publishes twenty domain indices, four pillar indices, a composite and six instruments. The composite never appears without every pillar and domain beside it, and no independent dimension is collapsed silently.
Classes with intervals, never league tables
Every value carries a 90% interval from Monte Carlo analysis over normalisation, weights, imputation and aggregation. Countries are placed in risk classes with a stated class probability; pages list countries by name or code, never by value.
No data is not zero
A missing input is shown as missing, an imputed input is flagged, and a value is withheld when coverage falls below the method's minimum. An empty profile, an unavailable source and an observed zero render differently.
Every value resolves to its source
Each value carries its source release, licence, retrieval time, method version and transformation chain (W3C PROV). A correction anywhere propagates to every dependent value and is logged publicly.
Measured, modelled and perceived are kept apart
Status glyphs separate observed, reported, estimated, inferred, forecast, simulated, scenario and expert input. Perception signals form their own instrument and are never blended into measured risk.
Systemic by construction
Standalone risk and coupling-adjusted risk are reported side by side, from typed dependency networks across trade, finance, energy, food, infrastructure and information.
Licence-gated and reproducible
A source enters a public value only when its licence admits that use; withheld values are counted, not hidden. Methods, code paths, seeds and digests are published per release so any value can be recomputed.
Information, not authority
NXS-GRX is research and risk-analytics information. It is not a rating, an official classification, a warning, a benchmark or advice, and it never decides for an institution.
Source to profile
Every indicator declares its place on the risk chain and its polarity, so aggregation never mixes directions silently.
- Event streamsSOURCES · SOURCES · near real timeAdmitted alert, Earth-observation, conflict-event, price and market streams for the Pulse instrument.
- 208 registered sourcesSOURCES · SOURCES · licence-gatedEvery source is registered with its licence; nothing enters a public value its licence does not admit.
- Scenario familiesSOURCES · SOURCES · labelledSocio-economic and warming pathways and transition families, used as labelled scenario structures.
- Surveys and elicitationSOURCES · SOURCES · perceptionStructured expert elicitation and public surveys, kept apart from measured risk.
- Dependency networkNETWORK · NETWORK · six layersTrade and input–output, finance and debt, energy, food trade, infrastructure and information links.
- Harmonised seriesHAR · HAR · units, areas, timeSource series mapped to Nexus concepts and code lists; units, areas and frequency aligned; no imputation.
- 451 indicatorsIND · IND · Indicator StandardNative indicators with definitions, units, polarity, levels and crosswalks; flagged imputation only here.
- 86 sub-indicesSUB · SUB · normalisedNormalised, weighted and aggregated components inside each domain.
- 20 domain indicesIDX · IDX · 1,000 drawsTwenty domain indices with Monte Carlo intervals and sensitivity.
- Systemic coupling scoreCOUPLING · COUPLING · SContagion on the dependency network: DebtRank, clearing and threshold cascades.
- Hazard and threat exposurePILLAR · PILLAR · HTEWhat can strike, how often, how hard and who and what stands in its way?
- Human and systems vulnerabilityPILLAR · PILLAR · VULHow susceptible are people, livelihoods, ecosystems and essential systems to harm when a shock arrives?
- Macro-financial and structural fragilityPILLAR · PILLAR · MSFHow much fiscal, financial, external, digital and technological room does the system have before stress turns into crisis?
- Lack of coping and adaptive capacityPILLAR · PILLAR · LCCCan institutions anticipate, absorb, respond, recover and adapt?
- PulseINSTRUMENT · INSTRUMENT · weeklyNowcast anomaly against each country's own history.
- OutlookINSTRUMENT · INSTRUMENT · 1 to 36 monthsCalibrated event probabilities with verification scorecards.
- TailINSTRUMENT · INSTRUMENT · exceedanceExceedance curves, return-period losses, catastrophic register.
- PathwaysINSTRUMENT · INSTRUMENT · to 2100Fan charts under named scenario families.
- PerceptionINSTRUMENT · INSTRUMENT · separatePerceived severity and the perception gap.
- NXS-GRX Composite RiskCOMPOSITE · COMPOSITE · geometricComposite = (HTE × VUL × MSF × LCC)^(1/4), each pillar on 0–10 floored at 0.1; pillar = expert-weighted geometric mean of its domain indices
- 195 country profilesPROFILES · PROFILES · classes, intervalsEvery domain, pillar and instrument per country, never ranked.
- 54 series indicesSERIES · SERIES · global to technologySpecialised indices from the same domain indices.
- API, tiles and bulk filesACCESS · ACCESS · machinePublic cut, SDMX keys, vector tiles, bulk files.
- NXS-GRX Coupled RiskCOMPOSITE · COMPOSITE · × (1 + κ·S)Coupled = Composite × (1 + κ·S), S = systemic coupling score in [0,1] from the dependency network, κ disclosed per release (baseline κ = 0.25); reported beside the standalone composite, never instead of it
Pillars and domain indices
Pillar values are expert-weighted geometric means of their domain indices (equal weights in the baseline, recorded per release); a pillar needs two thirds of its domains, otherwise it is withheld.
HTE · Hazard and threat exposure
VUL · Human and systems vulnerability
MSF · Macro-financial and structural fragility
LCC · Lack of coping and adaptive capacity
Composite and coupled composite
The composite never appears alone: profiles show each pillar and domain beside it.
- Composite
- Composite = (HTE × VUL × MSF × LCC)^(1/4), each pillar on 0–10 floored at 0.1; pillar = expert-weighted geometric mean of its domain indices
- Coupled composite
- Coupled = Composite × (1 + κ·S), S = systemic coupling score in [0,1] from the dependency network, κ disclosed per release (baseline κ = 0.25); reported beside the standalone composite, never instead of it
- Uncertainty
- 1,000 Monte Carlo runs over normalisation, weights, imputation, aggregation (geometric, arithmetic, Mazziotta–Pareto); 90% intervals; Sobol first-order and total-order indices per release
- Coverage
- Each pillar needs two thirds of its domain indices; otherwise the composite is withheld and the pillar shown alone
Classes and intervals, never league tables
A class is printed with its probability (share of Monte Carlo draws inside the class). Below 60% the adjacent class is printed too (for example High, 54% · Very high, 41%). Fixed bounds keep classes comparable across editions; intervals show when two countries cannot be told apart. Lists are ordered by name or code.
Ten construction steps
The steps follow the OECD/JRC handbook on composite indicators and the statistical audit practice of the JRC Competence Centre on Composite Indicators, referenced for method only.
One edition, run as a workflow
An edition is a run: the evidence cut freezes, sources pass the licence gate, 451 indicators are computed for 195 profiles, 1,000 draws give the intervals, and two approval gates stand before anything is published.
End to end on the longest path: about 20.9 d of proposed target service levels. Gates wait for the people named; bars with a fading end have no fixed length.
- Evidence cut frozenCut · NXS-GRX run service · 1 hourInput vintages pinnedNXS-GRX run servicePostgreSQL ledger (row-level security)
- Licence gateIngest · Licence register · 1 hourAdmitted, isolated or withheldLicence register
- Harmonise matrix · 150 sourcesIngest · NXS-GRX run service · 6 hoursUnits, areas, timeNXS-GRX run serviceindicator standard
- Indicators matrix · 451 × 195Indicators · NXS-GRX run service · 4 hoursDerivations, flagged imputationNXS-GRX run serviceindicator standard
- Sub-indices matrix · 86Indices · NXS-GRX run service · 1 hourNormalise, weight, aggregateNXS-GRX run serviceTested model kernels
- Domain indices matrix · 20Indices · NXS-GRX run service · 1 hourTwenty domain indicesNXS-GRX run serviceTested model kernels
- Coupling scoreIndices · NXS-GRX run service · 2 hoursDebtRank, clearing, cascadesDependency networkTested model kernels
- 1,000 Monte Carlo draws matrix · 1,000Uncertainty · Monte Carlo engine · 3 hoursWeights, normalisation, aggregation, imputationMonte Carlo engine
- Intervals, classes, SobolUncertainty · Monte Carlo engine · 1 hour90% intervals · Class probabilities · SensitivityMonte Carlo engine
- Statistical audit approvalReview · Independent reviewer · 10 daysCoherence, stabilityTested model kernels
- Steward review approvalReview · Stewards · 10 daysMethod, evidence, public-safe screenPostgreSQL ledger (row-level security)
- Profiles and series matrix · 195 + 59Publish · Foundry · 2 hoursPublished with intervalsPublic cut APINS-1 UNI catalogue
- Tiles and bulk filesPublish · Foundry · 2 hoursISO3, ADM1, ADM2, H3 · Deposit with DOIVector tilesZenodo deposit
| Artifact | Job | Who | Stage |
|---|---|---|---|
| Cut record | Evidence cut frozen | NXS-GRX run service | Cut |
| Withheld counts | Licence gate | Licence register | Ingest |
| HAR series | Harmonise | NXS-GRX run service | Ingest |
| IND values | Indicators | NXS-GRX run service | Indicators |
| SUB values | Sub-indices | NXS-GRX run service | Indices |
| IDX values | Domain indices | NXS-GRX run service | Indices |
| S per country | Coupling score | NXS-GRX run service | Indices |
| Draw set with seed | 1,000 Monte Carlo draws | Monte Carlo engine | Uncertainty |
| Uncertainty report | Intervals, classes, Sobol | Monte Carlo engine | Uncertainty |
| Audit note | Statistical audit | Independent reviewer | Review |
| Release decision | Steward review | Stewards | Review |
| Edition | Profiles and series | Foundry | Publish |
| Tiles | Tiles and bulk files | Foundry | Publish |
| DOI | Tiles and bulk files | Foundry | Publish |
Five aggregation shapes
Try them on the fiscal and public debt index: switch the aggregation and watch the class and interval move.
| Aggregation | What it does | Domain indices using it |
|---|---|---|
| geometric | Weighted geometric mean after a floor of 0.1: partial compensation, so weakness in one component cannot be fully offset by strength in another. | Fiscal and public debt risk · Climate physical hazard · Water security risk · Health security risk · Socio-economic vulnerability · Energy security risk · Infrastructure fragility · Cyber risk · Lack of coping capacity |
| mazziotta pareto | Mean adjusted by the spread across components (non-compensatory): unbalanced profiles read as riskier than balanced ones with the same mean. | Financial stability risk · Food insecurity risk · Conflict risk |
| arithmetic | Weighted arithmetic mean: full compensation, used where components are substitutes. | External dependence risk · Climate transition exposure · Environmental pressure · Displacement pressure · Governance weakness · Technology concentration risk |
| geometric complement | Complement of the geometric mean of complements: any single high exposure lifts the index, as for multi-hazard exposure. | Multi-hazard exposure |
| product | Product of normalised components: risk exists only where all components are present, as for space-weather exposure. | Space-weather exposure |
No data is not zero
Imputation happens only at the indicator layer and is always flagged: dimension mean, indicator median or multiple imputation, as each definition declares. Each composite caps the share of its weight that may rest on modelled or imputed inputs and withholds its value below its coverage minimum. Coverage is published as a vector per country and indicator, never as a single complete flag; fragile and small-island states are where gaps cluster, so their coverage is shown first.
Status and value states
| Glyph | Status | Means |
|---|---|---|
| ● | OBSERVED | Measured directly and published by the source |
| □ | REPORTED | Reported or declared by a publisher, not independently measured |
| ◆ | ESTIMATED | Estimated or modelled by a stated method |
| ▲ | INFERRED | Inferred from related signals |
| ◇ | FORECAST | Probabilistic statement about a future period |
| ◈ | SIMULATED | Output of a simulation or stochastic event set |
| ○ | SCENARIO | Conditional on a named scenario, not a prediction |
| ◎ | EXPERT INPUT | Structured expert judgement |
| Value state | Means |
|---|---|
PUBLISHED | Released in an edition with interval, class and sources |
NO_DATA | No admitted input; not a zero |
INSUFFICIENT_EVIDENCE | Coverage below the method minimum; value withheld |
WITHHELD | An input's licence or the public-safe screen does not admit public display; counted |
DEGRADED | Published with a stated quality limitation |
Pulse
- Question
- What has changed since the last structural cut?
- Cadence
- Weekly nowcast, event-driven between releases
- Method
- Mixed-frequency dynamic factor model over admitted event streams (multi-hazard alerts, Earth observation, conflict events, prices, shipping, market stress), expressed as a standardised anomaly against each country's own history.
- Outputs
- Pulse anomaly by domain
- Signals for review with their sources
- Threshold crossings for subscribers
- Status of outputs
- OBSERVEDINFERRED
Outlook
- Question
- How likely are defined adverse outcomes over a stated horizon?
- Cadence
- Monthly, horizons of 1, 3, 12 and 36 months
- Method
- Calibrated probabilistic ensembles (statistical, machine learning and structured expert elicitation) for defined events: conflict onset and escalation, acute food insecurity phase shifts, debt distress signals, disaster losses, displacement surges. Verified with Brier skill, reliability diagrams, ROC and CRPS against outcomes.
- Outputs
- Event probabilities with credible intervals
- Forecast verification scorecards
- Back-test record per model version
- Status of outputs
- FORECAST
Pathways
- Question
- How does risk move under alternative futures to 2030, 2050 and 2100?
- Cadence
- Each annual edition
- Method
- Pillar and domain values projected under SSP × warming-level combinations and central-bank-network transition scenario families (used as labelled scenario structures), with demographic, urbanisation, governance and conflict pathways; fan charts, not point paths.
- Outputs
- Fan charts per domain and pillar
- Scenario cascades
- Adaptation and transition levers
- Status of outputs
- SCENARIOSIMULATED
Tail
- Question
- What does the rare, severe end of the distribution look like?
- Cadence
- Each annual edition, event-updated
- Method
- Event loss tables and year loss tables, exceedance-probability curves, probable maximum loss at 1-in-100 and 1-in-250, expected shortfall, compound-event copulas and a register of low-probability, high-impact and global catastrophic risks.
- Outputs
- Exceedance curves and return-period losses where loss can be modelled
- Protection-gap readings
- Catastrophic and frontier risk register
- Status of outputs
- SIMULATEDMODELLED
Coupling
- Question
- Where does risk travel across systems and borders?
- Cadence
- Each annual edition, quarterly network refresh
- Method
- Typed multi-layer dependency network (trade and input–output, finance and debt, energy, food trade, infrastructure and digital links); contagion estimated with DebtRank, Eisenberg–Noe clearing and threshold cascades; systemic importance and exposure scores per country and system.
- Outputs
- Systemic coupling score S
- Coupled composite beside standalone
- Transmission paths with status and references
- Status of outputs
- ESTIMATEDSIMULATED
| WAT | ENE | FOO | HLT | BIO | FIN | TRD | INF | DIG | SEC | |
|---|---|---|---|---|---|---|---|---|---|---|
| Water | ||||||||||
| Energy | ||||||||||
| Food | ||||||||||
| Health | ||||||||||
| Biodiversity | ||||||||||
| Finance | ||||||||||
| Trade | ||||||||||
| Infrastructure | ||||||||||
| Digital | ||||||||||
| Security |
Perception
- Question
- Where does perceived risk differ from measured risk?
- Cadence
- Annual expert and public survey waves
- Method
- Structured expert elicitation and public risk surveys, published as their own dimension with a perception-versus-measured gap per domain; never blended into the composite.
- Outputs
- Perceived severity by domain and horizon
- Perception gap
- Respondent coverage statement
- Status of outputs
- EXPERT INPUTREPORTED
Six geographic levels
Validation in public
Back-testing of Structural and Outlook values against realised outcomes
Back-testing of Structural and Outlook values against realised outcomes: disaster mortality and losses, acute food insecurity phases, conflict onset and fatalities, debt distress episodes, displacement
Forecast verification with Brier skill score
Forecast verification with Brier skill score, reliability diagrams, ROC area and CRPS, published per model version
Independent statistical audit of each major methodology version (correlation structure
Independent statistical audit of each major methodology version (correlation structure, coherence, uncertainty and rank stability)
Golden-value tests for every kernel with hand derivations
Golden-value tests for every kernel with hand derivations, so a value can be recomputed by anyone
Country right of reply and public correction log
Country right of reply and public correction log
Revisions and corrections
Methodology carries a semantic version; a change that breaks comparability is back-cast where inputs allow, and a correction propagates to every dependent value with a public log entry.
Recompute any value
Each release publishes definitions, method versions, code paths, random seeds and content digests; every kernel is tested against hand-derived golden values.
- Indicator Standard
- 451 indicators · 106 composites · 501 crosswalks
- Hazard Standard
- 14 domains · 120 families · 905 hazards · 281 HIPs 2025 hazards
- model registry
- 670 methods in 23 fabrics
- Snapshot
saeedvaladbaygi/nexus-foundry@31a753f769a9b3262945d0a07888a960bd9c9ee2