The Demographic Transition Model (DTM) is one of the most important population theories studied in IB Geography. It explains how population growth changes over time as countries develop economically and socially. The model is frequently used in exams to analyse population trends, compare countries, and explain changes in birth and death rates.

The DTM is divided into five stages, each representing a different level of development and population growth pattern. Although not all countries follow the model exactly, it provides a useful framework for understanding global population change.

Stage 1 is characterised by high birth rates and high death rates, resulting in very low population growth. This stage is associated with pre-industrial societies where disease, famine, and poor sanitation kept life expectancy low. No country remains in Stage 1 today, but it is important for understanding historical population patterns.

Stage 2 shows a rapid increase in population growth. Death rates fall sharply due to improvements in healthcare, sanitation, and food supply, while birth rates remain high. Many low-income countries are currently in this stage. The gap between births and deaths creates rapid natural increase, which can place pressure on education, healthcare, and employment systems.

In Stage 3, birth rates begin to decline. This is linked to improved access to contraception, rising living costs, urbanisation, and increased education for women. Death rates continue to fall, but at a slower pace. Population growth remains positive but starts to slow down. Many middle-income countries are at this stage of the model.

Stage 4 is typical of high-income countries. Both birth and death rates are low, resulting in stable or very slow population growth. Families choose to have fewer children due to high living costs, career priorities, and widespread access to family planning. Life expectancy is high, and ageing populations become a key demographic issue.

Some geographers include Stage 5, where birth rates fall below death rates, leading to population decline. This stage is associated with very low fertility, ageing populations, and shrinking workforces. Countries in this stage may rely on immigration to maintain population size.

The Demographic Transition Model is a powerful tool in IB Geography, but it has limitations. It is based largely on European development patterns and does not account fully for migration, government policies, or cultural differences. Despite this, it remains highly effective for explaining long-term population change.

RevisionDojo helps IB Geography students apply the DTM confidently by linking theory to real-world examples and exam-style questions, ensuring strong analytical responses across the syllabus.