Population

Welcome to the Study of Population!

In Economics, when we talk about Population, we aren't just counting heads. We are looking at the people who produce goods (the labour force) and the people who buy them (consumers). Understanding how a population changes helps governments plan for schools, hospitals, and jobs.

Don’t worry if some of the terms sound technical at first—we will break them down into simple pieces together!

5.3.1 The Factors that Affect Population Growth

A country's population changes because of four main "taps" that let people in or out of the system. Imagine a bathtub: the water coming in increases the level, and the water going out decreases it.

1. Birth Rate

The number of live births per 1,000 of the population per year.
Example: If a country has a high birth rate, it usually means there are many young children.

2. Death Rate

The number of deaths per 1,000 of the population per year.
Example: Better healthcare and clean water usually lead to a lower death rate.

3. Immigration

People moving INTO a country to live there. (Think I for Incoming).

4. Emigration

People moving OUT of a country to live elsewhere. (Think E for Exit).

How to Calculate Change

To find out if a population is growing, we look at two things:

Natural Increase: This is \( \text{Birth Rate} - \text{Death Rate} \). If more people are born than die, the population grows naturally.

Net Migration: This is \( \text{Immigration} - \text{Emigration} \). If more people move in than leave, the population grows through migration.

Memory Aid: The "B-D-I-E" Rule

Births + Immigration = People added (+)
Deaths + Emigration = People lost (-)

Key Takeaway: Population grows when (Births + Immigration) is greater than (Deaths + Emigration).

5.3.2 Why Growth Rates Differ Between Countries

You might notice that some countries have huge families while others have very few children. Why does this happen?

Reasons for High Birth Rates (often in Developing Countries):

1. Lack of Education: Especially regarding family planning.
2. High Infant Mortality: Parents have more children because they fear some may not survive.
3. Children as Assets: In agricultural societies, children help work on farms or support parents in old age.
4. Religious/Social Beliefs: Some cultures encourage large families.

Reasons for Low Birth Rates (often in Developed Countries):

1. Cost of Raising Children: Children are expensive! In developed countries, they are often seen as "economic liabilities" rather than "assets."
2. Women in Careers: As more women enter the workforce and pursue education, they often choose to have children later in life.
3. Availability of Contraception: Easy access to family planning helps people choose their family size.

Reasons for Changes in Death Rates:

1. Healthcare: Better hospitals and vaccines lower the death rate.
2. Nutrition: Access to a healthy, steady food supply.
3. Sanitation: Clean water and proper sewage systems prevent diseases like cholera.
4. Living Standards: Safer housing and working conditions.

Quick Review Box

Common Mistake: Students often think "Population Growth" only means "Births." Remember to always check Net Migration (people moving in and out) as it can change a population very quickly!

5.3.3 The Effects of Changes in Size and Structure

When the population changes, it affects the economy in big ways. We look at two main things: Size and Structure.

The Concept of Optimum Population

Is more people always better? Not necessarily. Economics uses the idea of Optimum Population.

1. Under-populated: Too few people to use the country’s resources efficiently. (Example: A huge factory with only two workers.)
2. Over-populated: Too many people for the available resources, leading to low living standards. (Example: 50 people trying to share one pizza.)
3. Optimum Population: The "Goldilocks" point—just the right number of people to produce the highest possible output per head.

Changes in Age Distribution

The population is usually divided into three groups:
- Young Dependents: People aged 0–15 (not yet working).
- The Working Population: People aged 16–65 (the labour force).
- Elderly Dependents: People aged 65+ (retired).

The Dependency Ratio: This shows how many "non-workers" the "workers" have to support. If a country has an Aging Population (lots of elderly people), the working population has to pay higher taxes to fund pensions and healthcare.

Population Pyramids

A population pyramid is a graph that shows the age and gender of a population. You don't need to draw them for the exam, but you must be able to read them!

1. Wide Base: This means a high birth rate (lots of babies).
2. Narrow Base: This means a low birth rate.
3. Wide Top: This means people are living a long time (high life expectancy).
4. Straight/Column Shape: Usually found in developed countries with stable growth.

Did You Know?

Japan has one of the oldest populations in the world. This means they have a high dependency ratio because there are many retirees and fewer young workers to replace them!

Effects of Population Changes: Summary

If population increases:
- Pro: More consumers (higher demand) and more workers in the future.
- Con: Pressure on housing, schools, and the environment.

If population decreases:
- Pro: Less overcrowding and less pressure on resources.
- Con: "Gapping" in the labour market (not enough workers) and possible closure of schools due to fewer children.

Key Takeaway: The "best" population isn't the biggest one; it's the one that matches the country's resources (Optimum Population) and has a healthy balance of workers and dependents.

Great job finishing this chapter! Population is the heartbeat of the economy. Keep practicing reading those population pyramids, and you'll be an expert in no time!