Each index is the probability that two people drawn at random from a country belong to different groups. 0 means everyone shares the trait; 100 means almost no two people match.
Alesina, A., Devleeschauwer, A., Easterly, W., Kurlat, S., & Wacziarg, R. (2003). Fractionalization. Journal of Economic Growth, 8(2), 155–194.
doi:10.1023/A:1024471506938
None of this data is mine. Every figure on this map was computed and published by the five authors named above. This page only draws them.
It is an independent, non-commercial visualisation, not affiliated with, reviewed by or endorsed by those authors, the NBER, the Journal of Economic Growth or its publisher. Nothing has been added, adjusted, averaged or imputed: where the source records no value, the map shows none.
The indices were published in 2003 and built from source material gathered roughly between 1985 and 2001 — ethnic group counts largely from national censuses and the Encyclopædia Britannica, religious shares from around 2001.
They are not a measurement of any country today. Borders have moved and populations have shifted since; several states on this map did not exist, or did not exist in their present form, when the figures were compiled.