Population momentum
Topic: World Population: Distribution, Density, Growth and Migration · NCERT: Beyond NCERT
Meaning
Population momentum is the way a young population keeps growing for decades even after fertility falls to replacement level, which is about 2.1 children per woman. Earlier high fertility left a very large number of young people. As they enter child-bearing age, the total number of births stays high even though each woman has fewer children. So the population keeps rising until this large group grows old.
Example
India's total fertility rate fell to 2.0 in NFHS-5 (2019-21), which is below replacement level. India's population is still growing, because it has a very large number of young adults now having children.
Don't confuse with
- Natural growth of population: this measures births minus deaths at a given time. Population momentum explains why that growth continues after fertility has already fallen.
Related concepts
- World population growth trend
- World population of 8 billion
- World Population Prospects
- State of World Population report