The demographic transition model (ESS HL)

The demographic transition model at Higher Level: The same five stages as SL, with different places: Sweden, Brazil, Germany, South Korea and the Gulf states. At HL, explain why some countries pass through the stages far faster than others, and link each stage to the policy a government might choose.

Deaths fall first, then births: The demographic transition model (DTM) shows how a country's births and deaths change as it develops. Deaths fall first and births follow, so the population grows fast in the middle stages and levels off at the end.

Remember it as: Both high; deaths fall; births fall; both low; births below deaths.

Real example: Sweden has one of the world's longest records of births and deaths, kept since 1749. Its death rate began to fall around 1800 (stage 2), its birth rate from the 1880s (stage 3), and both were low by the 1930s (stage 4).

In stage 2 people stop dying young, but families still have many children. The gap between births and deaths, the natural increase, is at its widest.

Real example: in Brazil the death rate fell fast from the 1940s, while women still had about 6 children each in 1960. The population grew from about 41 million in 1940 to about 93 million in 1970.

Two traps: In stage 2 the death rate is falling, not yet low: do not write 'low death rate'.

'The birth rate is higher than the death rate' is true in stages 2, 3 and 4, so it does not prove stage 2 on its own.

In stage 3 families choose to have fewer children, while the death rate keeps falling. Growth slows, although the population still rises.

Real example: in Brazil from the 1960s most people moved to cities (about 87% live in them today), girls stayed longer at school, women took paid jobs and contraception spread. The fertility rate fell from about 6 children per woman in 1960 to about 1.6 by 2020.

Name the change and its cause: Write 'births fell because women stayed in school longer', not just 'education'. Say women's education or sex education. 'Less child labour' or 'fewer babies die' alone is not enough either: say how it cuts births.

As a population ages, fewer people are of child-bearing age, so births fall further.

Asked what moves a country from stage 2 to stage 3? Give reasons for the birth rate falling AND the death rate still falling: answers on only one rate are capped at 2 marks.

In stage 4 births and deaths are both low and the population stops growing. In stage 5 births fall below deaths, so without migration the population shrinks.

Real example: Germany has had more deaths than births every year since 1972, so it is in stage 5. Its population still grew, to about 84 million, because of immigration.

Stage 4 or stage 5?: Compare the two rates. About equal: stage 4. Births below deaths: stage 5. Because some versions of the model stop at four stages, a shrinking country may also be called stage 4.

To place a country on the DTM, use its birth and death rates, or the shape of its age-sex pyramid.

Describe the data, do not just copy it: Say 'a high birth rate of 38 per 1000', not just '38 per 1000'. In stage 2 the death rate is falling, not 'low'.

'Many children' is too vague: say 'the largest group is aged 0-4' or 'a wide base'.

Real example: about 22% of Germans are 65 or over and the base is narrow: stage 5. In Brazil the groups under 30 get smaller towards the base, while few people are over 60: stage 3.

Stage 3, not stage 4: A base that narrows under 30 shows falling births. If there are still few people over 50, and the sides curve inwards higher up because many died young in the past, it is stage 3: the country is moving from stage 2 to stage 4.

The DTM is a model: a simple picture of how populations changed in the past. Like every model, it helps, but it also leaves things out.

Real examples: about 1.3 million Swedes emigrated to North America between 1850 and 1930, and today close to 9 in 10 people living in the United Arab Emirates are foreign workers and their families. The DTM leaves migration out.

Fast and slow transitions: The UK took about 150 years from stage 2 to stage 4; South Korea took about 40. Its fertility rate fell from about 6 in 1960 to below replacement by 1983, because it imported vaccines and medicines, built industry and cities at great speed, and ran family planning from 1962.

A country's stage tells its government whether births and deaths are rising or falling. So it can predict growth and choose a policy to match.

Link it to the DTM: Every point needs the stage, or its birth and death rates: 'South Korea is in stage 5, with births below deaths, so it pays parents for each child.'

Technocentrists say technology has always let human numbers grow past their limits, raising the carrying capacity. The DTM partly agrees.

Real example: the Haber-Bosch process makes artificial fertiliser. The food it helps to grow feeds nearly half the world's people today.

A conclusion for a [9]: Technology largely overcame limits in the early stages, but Earth's carrying capacity is finite, and many populations now stabilise through economic and political choices, not new inventions.