Glossary
Population momentum
Population momentum is the tendency of a population to keep growing for decades after fertility falls below replacement level.
Why it happens
If a country has a large cohort of people currently of childbearing age, it keeps producing a lot of babies even when each of them has fewer children than their parents did.
The growth is coming from the number of parents, not the number of children each has.
Why it matters here
It is the single most common misreading of fertility statistics. A country can be below [[Replacement level fertility]] and still growing, for thirty years or more.
More terms
The date after which a model has no built-in knowledge.
The standard method for projecting a population by ageing each birth cohort…
Restricting access to a service or content by declared or verified age.
The number of people over 65 per 100 people under 15.
Fetching documents at question time and generating an answer grounded in them.
The cohort born between 2025 and 2039.