Demographic transition refers to the historical shift from high birth rates and high death rates in societies with minimal technology, education, and healthcare to low birth rates and low death rates in societies with advanced technology, education, and healthcare. The demographic transition model is a conceptual framework that explains why countries go through a period of rapid population growth and is based on historical population trends of two demographic characteristics: birth rate and death rate. The model describes the observed pattern in countries around the world and is one of the great insights of demography. The demographic transition model consists of five stages:
- Stage 1: Pre-transition
- Characterized by high birth rates and high fluctuating death rates.
- Population growth was kept low by Malthusian "preventative" (late age at marriage) and "positive" (famine, war, pestilence) checks.
- Stage 2: Early transition
- During the early stages of the transition, the death rate begins to fall.
- As birth rates remain high, the population starts to grow rapidly.
- Stage 3: Late transition
- Birth rates start to decline.
- The rate of population growth decelerates.
- Stage 4: Post-transition
- Post-transitional societies are characterized by low birth and low death rates.
- Population growth is negligible, or even enters a decline.
- Stage 5: The future
- Some demographers suggest that a fifth stage may be added to the demographic transition model, characterized by a very low birth rate and an aging population.
The demographic transition model helps demographers better understand a countrys current population growth based on its placement within one of the five stages and then pass on that data to be used for addressing economic and social policies within a country and across nations.
