2.7 Demographic Transition Model

What is the DTM?

The Demographic Transition Model (DTM) shows how a country's birth and death rates change over time as it industrializes and develops economically. It has five stages, moving from high birth/death rates to low birth/death rates. Population growth rate depends on the gap between CBR (crude birth rate) and CDR (crude death rate).

Stages 1-3: Death rates fall, births stay high

Stage 1 (Low Growth): high CBR and CDR, minimal growth — no country remains here today. Stage 2 (High Growth): CDR drops sharply due to improved sanitation/medicine while CBR stays high, causing rapid population growth. Stage 3 (Moderate Growth): CBR starts falling due to urbanization, education, and access to contraception, while CDR continues to decline slowly.

Stages 4-5: Low growth or decline

Stage 4 (Low Growth): CBR and CDR are both low and roughly equal, population stabilizes; most developed countries are here. Stage 5 (Decline): CBR falls below CDR, causing population decline — seen in countries like Japan and Germany. The model connects to the epidemiologic transition, which describes shifting causes of death across stages.

Key terms

Demographic Transition Model (DTM)

A model showing how birth and death rates change through five stages as a country develops economically.

Stage 2 of DTM

High growth stage: CDR drops sharply due to improved sanitation/medicine while CBR remains high.

Stage 5 of DTM

Population decline stage: CBR falls below CDR (e.g., Japan, Germany).

Crude Death Rate (CDR)

The number of deaths per 1,000 people in a population per year.

Epidemiologic transition model

A companion model to the DTM describing how leading causes of death shift from infectious diseases to chronic/degenerative diseases as a society develops.

Try an AP-style question

Which DTM stage?

1. Stage 3
2. Stage 2
3. Stage 1
4. Stage 4