Frequently Asked Questions
Common questions about the International Sovereignty Index.
What does the ISI measure?
The ISI measures the concentration of external dependencies for EU-27 member states across strategic axes (financial, energy, technology, defense, critical inputs, logistics). It uses a Herfindahl-Hirschman Index (HHI) framework where 0 = perfectly diversified and 1 = total concentration on a single source.
Is a high ISI score "bad"?
Not necessarily. A high score indicates high concentration — meaning the country depends heavily on a small number of external sources. Whether that is problematic depends on context: concentration on a stable allied partner is structurally different from concentration on an adversarial source. The ISI does not make that distinction.
How is the composite calculated?
The ISI composite is an unweighted arithmetic mean of all available axis scores for each country. No domain-weighting is applied. This means each axis contributes equally to the composite, regardless of strategic importance.
Why are some country-axis scores missing?
Data availability varies by axis and country. If a score shows as '—', it means the backend could not materialize a score for that combination. The composite is then computed over available axes only.
What do the classification thresholds mean?
Classifications follow standard HHI bands: ≥ 0.50 (Highly Concentrated), 0.25–0.49 (Moderately Concentrated), 0.15–0.24 (Mildly Concentrated), < 0.15 (Unconcentrated). These are descriptive labels, not risk assessments.
Does the frontend perform any calculation?
No. The frontend is a pure rendering layer. Every score, classification, warning, and description is served by the backend API. The frontend performs zero computation and contains zero business logic. Percentile rankings and deviation-from-mean indicators shown in the UI are the only client-side derivations, computed from the backend-provided scores.
What time period does the data cover?
The reference window is stated on every page (e.g., in the version/window labels). The data is a snapshot from that period and does not auto-update.
Can I compare countries across different axes?
Yes, but with caution. Each axis measures concentration in a different domain using potentially different data sources and methodologies. A score of 0.30 in Financial does not mean the same thing as 0.30 in Defense. Always check the axis detail page for context.
Where does the data come from?
Each axis uses one or more data channels (e.g., Eurostat trade data, IEA energy data). The specific sources are documented on each axis detail page under 'Data Sources & Channels'.
How do I report an error?
If you believe a score is incorrect, the issue is in the backend data pipeline, not in the frontend. Please report it via the project's GitHub repository.