Population | O Level Economics 2281 & IGCSE Economics 0455 | Detailed Free Notes To Score An A Star (A*)
5.3.1 Factors That Affect Population Growth
A. Birth Rate
- Definition: The number of live births per 1,000 people per year.
- Factors increasing birth rate:
- Lack of contraception and education.
- Cultural or religious encouragement for large families.
- High infant mortality (more children born as insurance).
- Agricultural economies needing more labor.
- Factors decreasing birth rate:
- Better female education and employment.
- Access to family planning.
- Urbanization and higher living costs.
B. Death Rate
- Definition: The number of deaths per 1,000 people per year.
- Factors increasing death rate:
- Poor healthcare, malnutrition, natural disasters.
- Conflict, disease outbreaks.
- Factors decreasing death rate:
- Medical advancements.
- Improved sanitation and clean water.
- Public health campaigns.
C. Net Migration
- Net Migration = Immigration − Emigration
- Immigration: Movement into a country.
- Emigration: Movement out of a country.
- Positive net migration increases population.
- Negative net migration decreases population.
D. Other Influencing Factors
- Government population policies (e.g., China’s one-child policy).
- Economic incentives for childbirth or migration.
- Climate and natural disasters affecting mortality and migration.
5.3.2 Reasons for Different Rates of Population Growth in Different Countries
| Factor | Developing Countries | Developed Countries |
|---|---|---|
| Birth Rate | High – lack of contraception, cultural norms | Low – family planning, high costs |
| Death Rate | Falling – improving healthcare but still variable | Low – advanced healthcare |
| Life Expectancy | Increasing, but still lower | High |
| Net Migration | Often negative (emigration) | Often positive (immigration) |
| Fertility Rate | High (>3 children/woman) | Low (<2 children/woman) |
| Population Growth Rate | Rapid growth | Slow growth or even decline |
Examples:
- Niger: High birth rate due to tradition and low contraception use.
- Japan: Negative growth due to ageing population and low fertility.
- USA: Slow growth mainly due to immigration.
- Pakistan: Rapid growth from high birth rates and falling death rates.
5.3.3 Effects of Changes in the Size and Structure of Population
A. Concept of Optimum Population
- Optimum population: The ideal number of people that can be supported by the available resources to maximize living standards.
- Underpopulation: Not enough workers = unused resources.
- Overpopulation: Too many people = strain on resources.
B. Effects of Increasing Population Size
| Positive Effects | Negative Effects |
|---|---|
| Larger labor force | Pressure on health, education |
| Bigger domestic market | Unemployment and underemployment |
| Potential for economic growth | Environmental degradation |
| Economies of scale | Congestion and housing shortage |
| Innovation from youthful population | Rising dependency burden if not matched by jobs |
C. Effects of Decreasing Population Size
| Positive Effects | Negative Effects |
|---|---|
| Less pressure on resources | Labour shortages |
| Less pollution | Slower economic growth |
| Higher wages due to competition | Difficulty funding pensions and healthcare |
| More space and housing | Ageing population increases dependency ratio |
D. Changes in Age Structure
- Youthful Population (e.g., Nigeria):
- High dependency ratio.
- Need for investment in education and jobs.
- Potential demographic dividend if managed well.
- Ageing Population (e.g., Japan, Germany):
- Increased healthcare and pension costs.
- Labour shortages.
- Shrinking tax base.
- May require raising retirement age or encouraging immigration.
E. Changes in Gender Distribution
- Gender Imbalances may occur due to:
- Cultural preference (e.g., for sons).
- War and conflict.
- Migration patterns (men migrate more for jobs).
- Effects:
- Marriage market distortions.
- Labour market gaps.
- Social issues and crime in severely imbalanced societies.
F. Population Pyramid Interpretation
- Wide base: High birth rate.
- Narrow top: Short life expectancy.
- Bulging middle: Working-age population peak.
- Inverted pyramid: Ageing population (e.g., Japan).
Note: You only need to interpret, not draw, population pyramids.
Exam Tip
- Clearly distinguish birth rate, death rate, net migration.
- Use country comparisons to explain differing growth rates.
- Link age structure to real economic problems (unemployment, pensions, etc.).
- Use optimum population to discuss under/overpopulation impacts.
- Practice reading population pyramids:
- Identify trends (e.g., ageing, youth bulge).
- Link to possible policy responses.
