Science
Demographic transition.
Definition
The demographic transition model describes how a country's population growth changes as it develops economically. It progresses through stages from high birth and death rates to low birth and death rates, with a period of rapid population growth in between.
How it works · 5 phases
Step by step.
- Stage 1: Both birth rates and death rates are high, so population growth is slow or stable.
- Stage 2: Death rates drop due to improved medicine, sanitation, and food supply, while birth rates remain high, causing rapid population growth.
- Stage 3: Birth rates begin to decline as urbanization increases and family planning becomes available.
- Stage 4: Both birth and death rates are low, leading to stable or slow population growth.
- Stage 5 (debated): Birth rates fall below death rates, causing population decline.
Examples
Real-world.
- 1 Many European countries like Germany are in Stage 4-5 with aging populations and low birth rates
- 2 Sub-Saharan African countries are largely in Stage 2-3 with declining death rates but still high birth rates
- 3 Japan is experiencing Stage 5 population decline with more deaths than births annually