How the Polystate Passport Power Index is calculated

What PPI measures — and what it does not

Most passport indexes answer one question: how many destinations can you enter without a visa?That is a tourist's question. The Polystate index answers a different one: how much practical mobility does this passport provide to someone optimising for freedom, opportunity, and jurisdictional optionality?

Two passports granting the same number of visa-free entries are not equivalent if one opens business hubs, capital centres, and viable residency pathways, and the other opens weekend-holiday destinations. PPI makes that distinction explicit.

Current version and what it covers

This is Version 1.1 of the index. Access data is ingested continuously from open datasets; destination weighting is applied from a versioned model maintained by Polystate Research. Every weight is rated against a published rubric, reviewed on a fixed quarterly cadence, and any change is recorded in the public changelog with per-country rationale.

Future versions will automate ingestion of the underlying public indexes used to set the quantitative dimensions; see the roadmap at the end of this document.

The scoring formula

For each passport P, the index computes a weighted sum across all destinations D the passport can reach without a full embassy visa:

where:

• access_weight(P,D) reflects the quality of the access granted. Visa-free entry scores 1.00. Electronic Travel Authorisation (ETA / ESTA / eVisitor) scores 0.85, because it retains a pre-screening step. Visa-on-arrival scores 0.70, because border refusal risk is materially non-zero. e-Visa, embassy visa, and no-admission categories score 0.
• destination_weight(D) is a composite score between 0 and 1 reflecting the utility of the destination to a globally mobile individual. See the five dimensions below.

The raw PPI value is normalised to a 0–1000 scale for presentation. We also display the unweighted visa-free destination count alongside PPI, so readers who prefer the traditional measure can see both.

Destination weighting: five dimensions

Each destination is rated on five dimensions, each bounded to the interval [0, 1]. Ratings are assigned against a published tier rubric using the reference indexes listed under each dimension. The composite destination weight is a weighted average of the five dimensions.

Data pipeline

PPI is produced by a versioned, reproducible pipeline. Access data is ingested programmatically from open datasets; destination weights are maintained as versioned data and edited only through reviewed change. Every change is recorded in the public changelog.

1. Access data ingestion. Visa requirement data is ingested from two open datasets — the primary source is ilyankou/passport-index-dataset, with imorte/passport-index-data used as a cross-check. Disagreements between the two are logged to an internal validation report; the primary source prevails unless overridden.
2. Destination weights. Weights are versioned internally. Each country is rated on five dimensions against the published tier rubric. The rubric, reference indexes, the dimension weights, and every change to the ratings are public.
3. Composition. The five dimensions are combined into a composite destination weight per country.
4. Computation. The PPI score for each of the 199 passports is computed server-side from the current visa-requirement data and current destination weights. Results are cached for fifteen minutes.
5. Publication. The index is served at /api/visa/ranking. The full tier rubric and every rating change are published on the methodology and changelog pages.

Update cadence and review policy

The index updates on two independent clocks:

• Visa rules are re-ingested monthly from the upstream datasets. Any change in visa policy between countries propagates to the index on the next ingestion cycle.
• Destination weights are reviewed quarterly (1 January, 1 April, 1 July, 1 October) against the reference indexes listed per dimension. Every review produces a published changelog entry with per-country rationale for any change.

Any weight change that moves a passport more than ten ranks in a single review requires written rationale in the changelog. The editorial dimension requires a second reviewer. No weight change lands on production without being recorded in the public changelog.

Editorial governance

Four of the five destination dimensions are rated against established public indexes using a published tier rubric. The fifth — the Sovereign Base Score— is editorial, and reflects Polystate's published thesis on sovereign mobility: that the value of a jurisdiction to a globally mobile individual depends on factors that no general-purpose index tracks. These include territorial or non-domicile taxation, extraterritorial tax liability, the availability of a credible residency pathway, capital-control posture, treatment of foreign income, and the political durability of favourable regimes.

Editorial ratings are changed only through reviewed change, accompanied by a written rationale citing specific legal or policy developments. Every change is recorded in the public changelog.

The editorial dimension is bounded to a weight of twenty percent of the composite destination score, so that no single editorial decision can override the quantitative signal from the other four dimensions.

Known limitations

We publish the limitations of the index openly, because they shape how it should be read.

• Aggregation bias. A single score cannot capture traveller-specific context. A passport strong for a tax-optimiser may be weak for a remote worker requiring specific healthcare systems, and vice versa.
• Annual-publication lag. Several reference indexes publish once per year. Fast-moving events (sanctions, coups, currency crises) are reflected in the visa data and in editorial overrides, but the quantitative dimensions may lag by up to twelve months.
• Dual citizenship unmodelled. PPI scores individual passports. It does not model the combined mobility of a citizen holding two or more passports, though this is a natural next step.
• Tourism versus residency. Visa-free access to a destination does not imply ease of obtaining residency there. PPI measures the former; residency programs are analysed separately on Polystate.

Reproducibility and changelog

Every published version of the index is tagged and archived. Weights are versioned internally; every change is recorded in the public changelog with rationale and specific tier movements.