5.3 Population
- IGCSE Economics
- Syllabus ref: 5.3 Population
Speaker notes: Introduce the topic of population and its importance in economic development. Ask students why population matters for an economy.
Learning objectives
- Define birth rate, death rate, natural increase and net migration.
- Explain factors that affect population growth.
- Describe how changes in population size and structure affect an economy.
- Calculate and interpret dependency ratios.
Speaker notes: Outline the learning objectives. Explain that students will learn how populations change and the economic effects of those changes.
Starter: A growing population
- In a fictional country, the population has doubled in 30 years.
- What problems and opportunities might this create?
Speaker notes: Pose the starter question to the class. Encourage discussion about the possible impacts of rapid population growth.
How populations change
- Birth rate: number of live births per 1,000 people per year.
- Death rate: number of deaths per 1,000 people per year.
- Natural increase = birth rate minus death rate.
- Net migration = immigration minus emigration.
- Population growth = natural increase + net migration.
Speaker notes: Explain the key measures of population change. Use simple examples to show how natural increase and net migration combine.
What affects birth rates?
- Income levels: higher income often lowers birth rates.
- Education and employment for women.
- Access to contraception and family planning.
- Cultural and religious beliefs.
- Government policies (e.g., incentives or limits).
Speaker notes: Discuss each factor that influences birth rates. Ask students to suggest examples from different countries.
What affects death rates?
- Healthcare quality and access.
- Nutrition and food supply.
- Sanitation and clean water.
- War, conflict and natural disasters.
- Age structure of the population.
Speaker notes: Explain how improvements in healthcare, nutrition and sanitation reduce death rates. Discuss the impact of conflict and disasters.
Migration and population change
- Immigration adds to population; emigration reduces it.
- Push factors: unemployment, poor living conditions, conflict.
- Pull factors: better jobs, higher wages, better services.
- Net migration can be positive or negative.
Speaker notes: Define migration and explain push and pull factors. Discuss how net migration can change a country's population.
Population structure
- Age and gender distribution shown in population pyramids.
- Wide base = high birth rate; narrow top = low life expectancy.
- Ageing population: high proportion of elderly.
- Youthful population: high proportion of young people.
Speaker notes: Introduce population pyramids. Explain how the shape shows the age and gender structure of a population.
Ageing populations: causes and effects
- Causes: low birth rates, longer life expectancy.
- Effects: higher healthcare and pension costs.
- Smaller labour force; possible labour shortages.
- Government may raise retirement age or encourage immigration.
Speaker notes: Discuss the causes and economic effects of an ageing population. Ask students to suggest government policies to address it.
Youthful populations: causes and effects
- Causes: high birth rates, lower life expectancy.
- Effects: pressure on schools and healthcare.
- Large future labour force if jobs are created.
- Risk of high unemployment and social unrest.
Speaker notes: Explain the causes and effects of a youthful population. Highlight both challenges and potential benefits.
Dependency ratio and its effects
- Dependency ratio = (young + old) / working-age population × 100.
- High ratio means more pressure on working population.
- Affects government spending on education, health, pensions.
- Changes in population size affect labour supply and demand.
Speaker notes: Explain the dependency ratio and how to calculate it. Discuss how a high ratio affects the working population and government.
Worked example: dependency ratio
- Fictional country A: 20 million aged 0-14, 10 million aged 65+, 30 million aged 15-64.
- Calculate dependency ratio: (20 + 10) / 30 × 100 = 100%.
- This means 100 dependents per 100 workers.
- High ratio: government may need higher taxes to fund services.
Speaker notes: Walk through the calculation step by step. Ask students to interpret what the result means for the fictional country.
Common mistakes and exam tips
- Do not confuse birth rate with natural increase.
- Remember net migration can be negative.
- Dependency ratio uses working-age population, not total.
- Use data accurately; show calculations.
- Link population changes to economic effects.
Speaker notes: Highlight common mistakes and give exam tips. Emphasise the importance of accurate definitions and clear calculations.
Key terms
- Birth rate: live births per 1,000 people per year.
- Death rate: deaths per 1,000 people per year.
- Natural increase: birth rate minus death rate.
- Net migration: immigration minus emigration.
- Dependency ratio: dependents per 100 workers.
- Ageing population: rising average age.
Speaker notes: Review the key terms. Ask students to define each term in their own words.
Quick check
- What is the formula for natural increase?
- Give two factors that can reduce birth rates.
- How does an ageing population affect government spending?
- What does a high dependency ratio indicate?
- How can migration affect the size of a population?
Speaker notes: Ask students to answer the quick-check questions. Use their responses to assess understanding.
Summary
- Population growth and structure are key to economic development.
Speaker notes: Summarise the main points of the lesson. Remind students that population changes have wide-ranging economic effects.