Girls' age at menarche linked to primary school enrollment gaps
Comparing Age population, age 13, female, interpolated with Primary education, pupils, gaps filled across 189 countries, 2025–2025.
- Rank correlation
- +0.99
- Holding size constant
- +0.79
- Countries compared
- 189
- Period
- 2025–2025
What might link these
A very strong rank correlation suggests a potential underlying link between adolescent girls' development and educational opportunities. However, the reduced but still significant correlation after controlling for population and GDP suggests other factors might be at play.
Why this is not proof of anything
This is a correlation across countries, not an experiment. It cannot show that either indicator causes the other, and both may simply follow a third thing. This relationship is a correlation and does not imply that one indicator directly causes the other; socioeconomic development is a likely confounder.
The second figure above repeats the measurement with national population and income held constant. It is the more conservative number: a relationship that largely disappears there was mostly telling you that larger, richer countries have more of most things.
How this was measured
Both indicators were ranked across every country reporting each, and the two rankings compared — ranks rather than raw values, because a handful of very large countries can otherwise manufacture a relationship on their own. The calculation is arithmetic over figures already published on this site; the commentary above is drafted from the two indicator names and the resulting coefficients.