Methodology

How to read the scale

Most country indices are expressed on a scale of 0–100 for readability, but not through a single formula. Depending on the dataset, the index page publishes min–max normalisation with outlier capping, an absolute scale, a weighted composite or log normalisation. Passport Index also shows the number of freely accessible destinations; Migration ROI uses log normalisation.

The 0–100 scale shows relative position within each index. A score of 80 on tax does not measure the same quantity as a score of 80 on healthcare. Only composite scores with a published formula and published weights add pillars together.

Three tiers of indices

Data principles

• Source priority government / intergovernmental / independent bodies.
• Entry rules checked against official government portals for each country, and we check that the links are still alive.
• The source name, version and data date are stated on each page; travel or programme claims must be re-checked at the official link before you act on them.
• Composite scores are published only once their component indices have been verified.
• Each index states data version and the date it was updated.

Updated & versioned

Entry rules and country indices change over time. With every update we tag a data version so you know which point in time the figures belong to. Coverage and the level of verification can differ between datasets and are stated on the corresponding page. Always verify with the official authority of the destination country before making a travel or investment decision.

What we không làm

• We neither copy nor directly compare against any other organisation's ranking — the method is our own.
• No ranking by sponsor; the data stays neutral towards every programme.
• We do not sell users' personal data to third parties.
• We give no legal, tax or investment advice — this is reference data for research.