Midlife men's population linked to earlier group's size
Comparing Population ages 45-49, male, annual growth rate with Population ages 35-39, male, per unit of GDP across 211 countries, 2025–2025.
- Rank correlation
- +0.61
- Holding size constant
- +0.52
- Countries compared
- 211
- Period
- 2025–2025
What might link these
The relationship between these indicators might be driven by demographic factors, such as changes in birth rates or mortality rates, which could influence both the size of the 35-39 age group and the subsequent growth rate of the 45-49 age group. A careful reader should consider the potential impact of urbanization or migration patterns, which could also affect these numbers. Education levels might be a confounder, as they can influence both economic productivity and family planning decisions.
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 correlation could mislead by implying a direct relationship between the two age groups without accounting for broader societal and economic trends.
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.