3.9 Demographic Transition

The Demographic Transition Model

The Demographic Transition Model (DTM) describes how a country's birth rate and death rate change as it industrializes, shifting from high birth/death rates to low birth/death rates. It has four (sometimes five) stages, moving from high population growth potential to stability, and is linked to a country's level of economic and technological development.

The Four Stages

Stage 1 (Pre-industrial): high birth and death rates, slow growth. Stage 2 (Transitional): death rates drop (better medicine/sanitation) while birth rates stay high, causing rapid growth. Stage 3 (Industrial): birth rates fall due to urbanization, education, and access to contraception, slowing growth. Stage 4 (Post-industrial): low birth and death rates, stable/slow-growing population.

Stage 5 and Real-World Limits

Some models add Stage 5, where birth rates fall below death rates, causing population decline (e.g., Japan, some European nations). The DTM is a generalized model based on Western Europe's history and may not perfectly predict trends in all developing countries today, since technology can speed transitions unlike historically.

Key terms

Demographic Transition Model (DTM)

A model describing how birth and death rates change as a country industrializes and develops economically.

Stage 1 of the DTM

Pre-industrial stage: high birth rates and high death rates, resulting in slow population growth.

Stage 2 of the DTM

Transitional stage: death rates fall due to better medicine/sanitation, birth rates stay high, causing rapid growth.

Stage 4 of the DTM

Post-industrial stage: low birth rates and low death rates, leading to a stable or slow-growing population.

Stage 5 of the DTM

An additional stage where birth rates fall below death rates, causing population decline (e.g., Japan).

Try an AP-style question

In stage 2 of the demographic transition, what changes first?

1. Death rates fall while birth rates stay high
2. Birth rates fall while death rates stay high
3. Both rates rise
4. Both rates stay high