Geography (0460) | Population structure

IGCSE Geography (0460) Study Notes: 1.3 Population Structure

Hello Geographers! This chapter is all about understanding the "shape" of a country's population. It's like looking at a family portrait and figuring out how many kids, parents, and grandparents there are. This structure tells us a huge amount about a country's wealth, health, and future challenges. Ready to decode the pyramid? Let’s go!

What is Population Structure?

The Population Structure refers to the makeup of a population in terms of age and sex (gender).
It is usually represented by a specific type of diagram called the Age/Sex Pyramid (often just called a Population Pyramid).

Why is studying structure important?

Understanding the structure allows governments and planners to see:

• The current needs (e.g., more schools for children, or more pensions for the elderly).
• The future challenges (e.g., a shrinking workforce or an increasing need for healthcare).
• The country's current level of economic development (LEDC or MEDC).

Understanding the Population Pyramid

A population pyramid is the most essential tool for visualizing population structure. It’s not really a pyramid in all cases, but it gives a clear, visual snapshot.

The Components of the Pyramid

Don't worry if this diagram seems tricky at first—it’s just a bar chart turned on its side!

1. The Vertical Axis (Y-axis): Shows the Age Cohorts (groups). These are typically divided into 5-year intervals (e.g., 0-4, 5-9, 10-14, etc.). The oldest age groups are always at the top.
2. The Horizontal Axis (X-axis): Shows the Number or Percentage of people in that age cohort. The numbers increase as you move away from the center line.
3. The Center Line: Splits the population into Males (usually on the left) and Females (usually on the right).

Quick Tip: When analyzing a pyramid, look at three things: the base (births), the sides (death rates/life expectancy), and the top (oldest survivors).

Identifying Key Population Groups

We classify the population into three main groups based on whether they are economically productive:

1. Young Dependents (0-14 years): These people are too young to work and rely on the working population for food, housing, and education. (Found at the bottom of the pyramid).
2. Economically Active/Working Population (15-64 years): These are the people who typically work, earn money, and pay taxes. They support the dependents. (Found in the middle sections).
3. Elderly Dependents (65+ years): These people have retired and rely on pensions and healthcare supported by the working population. (Found at the top of the pyramid).

The relationship between the dependent groups (1 and 3) and the working group (2) is measured using the Dependency Ratio. A high dependency ratio means a large burden is placed on the workforce.

Different Types of Population Structures

The shape of the pyramid tells us which stage of development a country is likely in. Generally, we look at structures typical of Less Economically Developed Countries (LEDCs) and More Economically Developed Countries (MEDCs).

1. Structure Typical of LEDCs (The Wide-Based Pyramid)

This shape looks like a traditional, wide-based pyramid or triangle.

• Base: Very wide, showing a high Birth Rate (BR). Reasons include lack of family planning, need for children to work, and religious/cultural beliefs.
• Sides: Tapering quickly inwards, showing a high Death Rate (DR) in younger age groups. This is often due to poor sanitation, disease, and limited medical care.
• Top: Very narrow, indicating low Life Expectancy, as few people survive to old age.
• Dominant Group: High Young Dependent Population.

Example: A country like Niger or Uganda typically exhibits this structure.

2. Structure Typical of MEDCs (The Barrel or Beehive Shape)

This shape is wider in the middle and often bulges towards the top, resembling a barrel or column.

• Base: Narrow or shrinking, showing a low or declining Birth Rate (BR). Reasons include high cost of raising children, career focus, and effective family planning.
• Sides: Straighter, showing a low Death Rate (DR) throughout most age groups, thanks to good healthcare and diet.
• Top: Wide, indicating a very high Life Expectancy, as many people live into their 80s and 90s.
• Dominant Group: High Elderly Dependent Population (Ageing population).

Example: A country like Japan or Germany typically exhibits this structure.

Implications of Different Population Structures

The specific shape of the pyramid leads to different social, economic, and political challenges for the country. You must be able to discuss these implications.

A. Implications of a High Young Dependent Population (LEDCs)

When the base is very wide, the country faces challenges related to youth:

1. Economic Strain:

• High Costs: Massive spending needed on primary education (building schools, training teachers) and basic healthcare (vaccinations).
• Low Productivity: The large non-working population means the workforce (15-64) has fewer people paying taxes to fund all these services.
• Future Unemployment: As these young people reach working age, the country needs to create millions of new jobs quickly, which is difficult for developing economies.

2. Social Strain:

• Housing: Rapid demand for new housing and infrastructure.
• Food Supply: Greater demand for food, which can lead to food insecurity if production cannot keep up.

B. Implications of a High Elderly Dependent Population (MEDCs)

When the top is wide and the middle/base are narrow, the country faces challenges related to ageing:

1. Economic Strain:

• Pension Crisis: Fewer workers supporting more retirees means the pension fund can run out, requiring increased taxes on the working generation.
• High Healthcare Costs: Older people generally require more frequent and specialized medical care (e.g., long-term care homes, treatment for chronic diseases).
• Workforce Shortage: There may not be enough people of working age to fill jobs, leading to economic slowdown.

2. Social Strain:

• Service Provision: Need for specialized services like geriatric wards and accessible public transport.
• Changing Family Roles: The burden of caring for elderly relatives often falls on middle-aged children.

Case Study Focus: A Country with a High Dependent Population

For your case study, you must select a country that demonstrates the challenges associated with a very high proportion of dependents. We will focus on a country with youth dependency, as this is a common case study illustrating rapid growth (see 1.1 Population Dynamics).

(Note: You must choose a specific country, such as Nigeria or Uganda, and memorize the specific statistics and details for your exams.)

Case Study Analysis Framework: Youth Dependency (e.g., in a Sub-Saharan African Country)

1. Background and Structure:

• Structure: Classic triangular pyramid shape.
• BR: Extremely high (e.g., 40+ per 1,000).
• Life Expectancy: Low (e.g., under 60 years).
• Dependency Ratio: Very high (often over 80%).
• Key Statistic: Up to 45% of the population may be under the age of 15.

2. Reasons for High Dependency:

The high proportion of young people is primarily due to the very high birth rate, driven by social and economic factors:

• Economic Value: Children are needed to work on farms and provide income for the family.
• Lack of Contraception/Education: Poor access to family planning services and low levels of female education.
• Infant Mortality: High Infant Mortality Rate (IMR) means parents have more children, hoping some will survive to support them in old age.

3. Specific Implications (Challenges):

A large youth population creates immense pressure on resources:

Social Challenges:

• Education Overload: Schools are overcrowded, meaning larger class sizes and lower quality education. Many children may not attend school at all.
• Infrastructure Strain: Governments struggle to provide clean water, sanitation, and electricity to the rapidly growing number of households.

Economic Challenges:

• Slow Development: The majority of the national budget is spent on supporting young people rather than investing in industrial development or job creation.
• Poverty Cycle: Large families struggle to feed and educate all their children, perpetuating the cycle of poverty.