Age–Sex Pyramids and Population Analysis
Age–sex pyramids visually represent the distribution of different age groups in a population, categorized by gender.
These pyramids help identify trends in population growth, aging, and economic sustainability.
Dependency Ratio
Definition
Dependency ratio
The dependency ratio is a measure of the proportion of dependents (people under 15 and over 64) to the working-age population (15–64 years). It is calculated as:
$$\text{Dependency Ratio} = \frac{\text{Population aged 0–14 and 65+}}{\text{Population aged 15–64}} \times 100$$
Impact of High and Low Dependency Ratios:
- High Dependency Ratio:
- Found in countries with very high birth rates (e.g., Niger, Uganda) or aging populations (e.g., Japan, Italy).
- It increases the economic burden on the working-age population.
- Low Dependency Ratio:
- Occurs in countries with a balanced working-age population.
- It leads to economic growth potential (e.g., India’s demographic dividend).
Population Momentum
Definition
Population momentum
Population momentum refers to continued population growth even if the fertility rate declines.
It occurs because a large proportion of the population is in reproductive age, ensuring that births continue for several decades.Example
- China: Despite implementing the one-child policy (1979–2015), the population continued to grow due to a high number of young women entering reproductive age.
- India: Even though fertility rates have declined, a large base of young people ensures continued growth before eventual stabilization.
