Sociology
Demographic Momentum and the Challenges of Population Momentum in Developing Nations
Quick fact
Population growth from momentum can be so strong that, even if the average number of children per woman instantly falls to replacement level, a country's population can still increase by 30-50% over the next few decades—especially in developing nations with very young age structures.
Why this is interesting
You might think that once a country’s fertility rate drops to replacement level—about 2 children per woman—population growth would stop. But in many developing nations, the population continues to grow for decades, even after such a drop. Why?