Question

What is meant by population momentum, and what is its cause?

Short answer

Population Momentum refers to the continued population growth at the national level even after fertility rates have declined to 'replacement level'. Its cause is largely twofold: firstly, a significant base of young people who will likely have offspring in the future, and secondly, increased life spans due to medical advancements and improved quality of life.

Step-by-step solution

Understanding Population Momentum

Population Momentum refers to the tendency of a population to continue to grow even after fertility rates have declined to 'replacement level' due to the young age structure. It is a phenomenon commonly seen in human populations. Simply, it's the inertia that keeps the population growing even though the growth rate has slowed.

Causes of Population Momentum

There are two key factors that cause population momentum. One is the large base of young people. If a country's population has a large number of young individuals, they will likely have children in the future, contributing to the population increase. The other factor is longevity. As medical advancements continue and quality of life improves in many countries, people are living longer. This also contributes to population growth, as even though the birth rates may fall, the death rates may also decrease due to longer life spans.