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🌍 Topic 1.3:- POPULATION STRUCTURE

🔑 1. Key Terms & Definitions​

  • Population Structure: The composition of a population by age and sex.
  • Age Groups:
    • 0–14 → Young dependents
    • 15–64 → Economically active (working population)
    • 65+ → Elderly dependents
  • Dependency Ratio: Ratio of dependents (young + old) to the working population.
  • Dependent Population: People who rely on others for support (children + elderly).
  • Economically Active Population: People able to work and earn income.

📊 2. Age-Sex Pyramid (Population Pyramid)​

A population pyramid shows:

  • Age groups (vertical axis)
  • Population size (horizontal axis)
  • Males (left) and females (right)

🔺 Types of Population Pyramids​

🟢 1. Expansive (Rapid Growth)​

Shape: Wide base, narrow top

Features:​

  • High birth rate
  • High death rate
  • Short life expectancy
  • Large number of young people

Example:​

  • Nigeria

Implications:​

  • High dependency ratio
  • Pressure on schools and healthcare
  • Future population growth likely

🟡 2. Stationary (Stable Population)​

Shape: Rectangular

Features:​

  • Low birth rate
  • Low death rate
  • Stable population

Example:​

  • France

Implications:​

  • Balanced workforce
  • Steady economic growth

🔵 3. Constrictive (Declining Population)​

Shape: Narrow base, wider middle/top

Features:​

  • Very low birth rate
  • Ageing population
  • Long life expectancy

Example:​

  • Japan

Implications:​

  • Labour shortages
  • High pension costs
  • Ageing population problems

⚖️ 3. Reasons for Different Population Structures​

🌍 In Developing Countries:​

  • High birth rates:
    • Children needed for labour
    • Limited access to contraception
  • Higher death rates:
    • Poor healthcare
  • Result:
    👉 Expansive pyramid

🌎 In Developed Countries:​

  • Low birth rates:
    • Career focus
    • Cost of living
  • Low death rates:
    • Advanced healthcare
  • Result:
    👉 Constrictive or stationary pyramid

📉 4. Dependency Ratio​

Formula:​

Types:​

  • Youth Dependency → many children
  • Old-age Dependency → many elderly

Implications:​

High Dependency Ratio:​

  • More strain on working population
  • Increased government spending

Low Dependency Ratio:​

  • More workers → economic growth

🌍 5. Implications of Different Population Structures​

🔴 Youthful Population​

Advantages:​

  • Large future workforce
  • Potential economic growth

Disadvantages:​

  • High cost of education
  • High unemployment risk

🔵 Ageing Population​

Advantages:​

  • Experienced workforce
  • Stability

Disadvantages:​

  • Increased healthcare costs
  • Pension burden
  • Labour shortages

👩‍👩‍👦 6. Gender (Sex) Structure​

  • Usually slightly more males at birth
  • Females tend to live longer

Imbalances may be caused by:​

  • Migration (more males moving for work)
  • Cultural preferences
  • War (loss of males)

📚 7. CASE STUDY: High Dependent Population​

🇰🇪 Country: Kenya​

📊 Population Structure:​

  • Wide base (many young people)
  • High youth dependency ratio

📌 Reasons:​

  1. High Birth Rate
    • Cultural value of large families
    • Limited access to contraception
  2. Declining Death Rate
    • Improved healthcare
  3. Early Marriage
    • Leads to more children

📊 Impacts:​

On Economy:​

  • High unemployment
  • Pressure on government resources

On Services:​

  • Overcrowded schools
  • Strained healthcare systems

On Development:​

  • Slower economic growth
  • Need for more infrastructure

🌟 Opportunities:​

  • Large future workforce
  • Potential for economic growth if jobs are created

🧠 8. Exam Tips (VERY IMPORTANT)​

✍️ “Describe a population pyramid”​

  • Mention:
    • Shape (wide/narrow base)
    • Birth rate
    • Death rate
    • Life expectancy

✍️ “Explain reasons for structure”​

  • Link to:
    • Birth rate
    • Death rate
    • Economic development

✍️ “Implications questions”​

  • Cover:
    • Economic effects
    • Social effects
    • Government challenges

✍️ Case Study Questions:​

Include:

  • Country name
  • Key features (young/old population)
  • Reasons
  • Impacts

⚠️ Common Mistakes:​

  • Not linking structure to development level
  • Forgetting dependency ratio
  • Describing without explaining
  • No examples

🧩 9. Quick Summary​

Population structure shows:

  • Age distribution
  • Gender balance

Different shapes:

  • Expansive → growing
  • Stationary → stable
  • Constrictive → declining

Key impacts:

  • Workforce size
  • Economic growth
  • Pressure on services