The Demographic Transition Model (DTM)

The Demographic Transition Model describes how populations change over time as countries develop economically. CCEA examiners expect you to explain each stage, give examples of countries at different stages, and discuss Stage 5 (the case of countries like Italy and Germany where populations are declining).

The five stages of the DTM

Stage 1 — High fluctuating (pre-industrial):

• High birth rate AND high death rate → population grows very slowly.
• High death rate due to disease, famine, war, poor sanitation.
• High birth rate because children are economic assets (work in fields), there is no contraception, and high infant mortality means parents have many children hoping some survive.
• No country is in Stage 1 today; pre-industrial UK was in Stage 1.

Stage 2 — Early expanding:

• Birth rate stays high; death rate falls rapidly → population grows quickly.
• Death rate falls due to improved medical care (vaccines, antibiotics), better sanitation (sewers), improved food supply (agricultural improvements).
• Many Sub-Saharan African countries (e.g. Chad, Niger) are in Stage 2.

Stage 3 — Late expanding:

• Birth rate falls; death rate continues to fall slowly → population still grows but more slowly.
• Birth rate falls as countries urbanise (children cost more in cities), women gain access to education and contraception, infant mortality falls so parents don't need as many children.
• Brazil and India are broadly in Stage 3.

Stage 4 — Low fluctuating:

• Low birth rate AND low death rate → population stable or very slowly growing.
• Wealthy, developed nations. UK, USA, Australia.

Stage 5 — Decline:

• Birth rate falls BELOW the death rate → population declines (negative natural increase).
• Examples: Germany, Italy, Japan, Russia.
• Causes: very high cost of raising children; high female employment; cultural change (prioritising career over large families); excellent contraception access.

Population pyramids and the DTM

Each stage has a characteristic population pyramid shape:

• Stage 1: wide base (many children), narrow top (few elderly) — triangular.
• Stage 2-3: wide base, narrowing top — still roughly triangular but less extreme.
• Stage 4: more rectangular — similar proportions at each age group.
• Stage 5: narrow base (few children), wider middle and top — bullet or urn shape.

Stage 5 — Italy and Germany (CCEA focus)

Italy has a total fertility rate of approximately 1.2 (2023). Germany's is approximately 1.4. Both are well below the replacement rate of 2.1. The consequences:

• An ageing population with increasing dependency ratio (fewer workers supporting more retirees).
• Strain on pension systems and healthcare.
• Labour shortages — addressed partly through immigration.
• Potential for economic stagnation.

Northern Ireland context: NI's fertility rate is slightly higher than the rest of the UK (~1.7) but still below replacement. Immigration to NI has significantly increased in recent decades, affecting population composition.