What does population momentum refer to?

Population momentum refers to the phenomenon of continued population growth even after a reduction in birth rates has occurred. This occurs because a significant proportion of the population is still in reproductive age, resulting in a natural increase as they continue to have children. This growth continues for several decades, driven by the existing age structure of the population. Therefore, even if a society implements measures to reduce fertility rates, the effects may not be immediately visible, as past higher birth rates have already created a large base of young people who will contribute to population growth.

Understanding population momentum is crucial for planning and policy-making, especially in regions experiencing rapid demographic shifts, as the effects of population policies may take years to materialize.