Eurostat-derived inputs remain the backbone of the exact ESS targets. Comext and the official partner API support supplier analysis; World Bank, OECD, Wikipedia and screened-news variables are explanatory experiment features and do not replace the target formulas.
Source hierarchy
| Layer | Role | Publication treatment |
|---|---|---|
| Eurostat energy and GDP inputs | Exact ESS formula backbone and comparison metrics | Primary target evidence |
| Raw Comext | Selected product-partner value and mass shares | Preferred replication layer when populated |
| Official partner API | Reproducible annual partner quantities | Use within the API route's precise scope |
| Published workbook | Published-figure comparison and selected 2025 context | Keep direct and derived figures distinct |
| External APIs and event features | Lagged explanatory variables in experiments | Do not present as exact ESS inputs or causal effects |
Forecast validation
Candidate baselines include long and recent linear trends, average and weighted annual-change drift, and the last observed value. Rolling-origin backtests compare historical forecasts with later observations. The selected model is trained on all available history only after the model family is chosen.
Scenario adjustments are applied after the baseline. Forecast-quality reporting distinguishes nested historical selection evidence from the final forward path.
Limitations and interpretation guardrails
- ESS values are internally consistent project indices, not official physical dependency percentages.
- Country comparisons inherit the coverage, unit and revision limits of their source inputs.
- Quantity shares across unlike energy products must not be added as if they used one physical energy unit.
- Scenario paths are exploratory, not point predictions or causal policy-impact estimates.
- External news and Wikipedia layers are screening or explanatory features, not verified causal treatment data.
- Freshness claims are allowed only when build metadata confirms a live refresh for the relevant source.
Publication controls
The public website reports only curated summaries. Detailed generated artifacts, source code, raw extracts and commercial operating materials remain governed by the project license and their respective source terms.