Method
One number, one formula, and a receipt for every claim.
The Effective Cost Index
ECI = local monthly price ÷ monthly GNI per capita × 100
ECI = local monthly price ÷ monthly per-capita income × 100
The answer reads as a share: an ECI of 1.5 means the subscription costs one and a half percent of a month of per-capita income.
The denominator
GNI per capita, current local currency, from the World Bank — free, keyless, and covering every country with sixty years of history. Divided by twelve for a month.
This is an average per person, not a median wage. A median would be better but is not available free and comparable across every market. The number is therefore about the size of a typical share, not a typical salary.
The numerator
The price on the service's own page, in the market's own currency, read by a person and written down with a date.
No price is published without a date and a link to the page it was read from. When a price is not verified it is not shown as a price.
How the watching works
A nightly job fetches each pricing page and hashes it. When the hash changes, a person is told to go and re-read the price. The machine never writes a price.
fetch → hash → changed? → alert a human → human re-reads → price written down
Coverage right now
How much of the database has been checked in the last 30 days.