Key Idea: Most marks in topic 8.1 come from calculating population change and the demographic transition model. Then learn population policies and how education and jobs slow growth.
1. Measuring change (most marks)
- NIR (%) = (CBR − CDR) ÷ 10. Always give the unit: % or per 1000.
- Doubling time = 70 ÷ growth rate (%): Niger grows about 3.3% a year, so it doubles in about 21 years.
- Japan, 2024: births 5.7 and deaths 13.3 per 1000, so NIR = −0.76% and it is shrinking.
2. The demographic transition model
- Stage 2: the death rate falls (food, vaccines, clean water) but births stay high, so growth is fast.
- Stage 3: the birth rate falls (school, contraception, city life). Stage 4: both low, about 10 per 1000.
- Stage 5: deaths exceed births: Germany since 1972, Japan since 2007.
3. Policies and indirect management
- Direct policies: China's one-child policy (1980-2015); Singapore's Baby Bonus (since 2001).
- Indirect: educate girls and give women jobs. In Kerala about 92% of women read and have about 1.8 children.
- Pyramids: a wide base means many children and fast growth; a narrow base means an ageing population.
How it is examined:
| Question | How to score |
|---|---|
| [1] Calculate an NIR or a doubling time | NIR = (CBR − CDR) ÷ 10; doubling time = 70 ÷ NIR %. Show working and the unit. |
| [4] Distinguish CBR from NIR or from TFR | CBR is births per 1000 people; NIR takes away deaths; TFR is children per woman. |
| [1] to [3] Place a country on the DTM | Quote its birth and death rates or pyramid shape, then name the stage. |
| [2] to [3] Suggest how a pyramid will change | Wide base: growth ahead. Narrow base: ageing. Give the reason. |
| [7] Explain how policies raise or lower growth | Direct (laws, money) and indirect (school, jobs), with named countries. |
| [9] To what extent can policies stabilise population? | Successes, failures and side effects, then a judgement. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Crude birth rate (CBR) | live births per 1000 people per year |
| Crude death rate (CDR) | deaths per 1000 people per year |
| Natural increase rate (NIR) | the birth rate minus the death rate, per 1000 or as a percentage |
| Total fertility rate (TFR) | the average number of children a woman has in her lifetime |
| Doubling time | the years a population takes to double at its present growth rate |
Last-minute check: answer, then tap to see.
CBR 38 and CDR 8 per 1000. What is the NIR? (38 − 8) ÷ 10 = 3.0% a year.
A country grows by 2% a year. What is its doubling time? 70 ÷ 2 = 35 years.
Why does the death rate fall in stage 2? Better food, vaccines and clean water.
Why did the one-child policy leave more boys than girls? Many families wanted sons: about 120 boys were born per 100 girls in the 2000s.
In Brazil the death rate fell fast from the 1940s, but women still had about 6 children each in 1960. Explain how a country's population changes as it moves from stage 2 to stage 4 of the demographic transition model.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- For a calculation, write the formula, show the working and give the unit.
- Say 'a high birth rate of 38 per 1000', not just the number.
- In stage 2 the death rate is falling, not yet low.
- For a policy, name the country and the years, and say whether it worked.