Demographic transition

Science

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

  1. Stage 1: Both birth rates and death rates are high, so population growth is slow or stable.
  2. Stage 2: Death rates drop due to improved medicine, sanitation, and food supply, while birth rates remain high, causing rapid population growth.
  3. Stage 3: Birth rates begin to decline as urbanization increases and family planning becomes available.
  4. Stage 4: Both birth and death rates are low, leading to stable or slow population growth.
  5. Stage 5 (debated): Birth rates fall below death rates, causing population decline.

Examples

  • Many European countries like Germany are in Stage 4-5 with aging populations and low birth rates
  • Sub-Saharan African countries are largely in Stage 2-3 with declining death rates but still high birth rates
  • Japan is experiencing Stage 5 population decline with more deaths than births annually

Related Terms

Population growth Population dynamics Urbanization Carrying capacity

Study This Concept

Practice demographic transition with free review games in these units:

AP Environmental Science Unit 3: Populations