Methodology

A shared 0–100 scale

Every index onto one scale 0–100 using min–max normalisation: the country with the highest value scores 100, the lowest scores 0, and everything else falls linearly in between. Where a low value is the good outcome (tax burden, for example), the scale is inverted.

Example — the Passport Index: "strength" = the number of destinations reachable visa-free, with visa on arrival or with an eTA. The strongest passport (Singapore) scores 100; every other passport is scaled against the highest–lowest range.

Because they share one scale and one country list (keyed on ISO 3166-1 alpha-3), so every index genuinely comparable with each other and can be combined into composites without mixing units.

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• The source directory is kept in an internal register, which we do not publish in full (it protects the research behind it); we do state method, and we do not circulate the source list.
• 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 indicators change over time. With each update we stamp a data version so you know which vintage a figure belongs to. Long lists (e-Visa and VOA, for instance) are sample-checked before publication. Even so, always verify with the destination's own authority 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.