Every government in the world is chasing the same number. Growth gets reported on the news, wins and loses elections, and decides which policies get funded. So it is worth knowing exactly what that number counts — and, more importantly, what it quietly leaves out.
📚 What you need to know
Economic growth is the increase in the total market value of goods and services produced in a country over a period of time.
It is normally measured as the annual percentage change in gross domestic product (GDP).
GDP is the monetary value of everything produced inside a country’s borders in a year. It can be worked out by the expenditure approach or the income approach, and both should give the same total.
Per capita GDP = GDP ÷ population. It is the average income per person, which makes comparing countries easier — but it hides how unevenly that income is shared.
Positive growth means the economy is expanding; negative growth means it is contracting.
The traditional linear model pushes production and consumption up without accounting for the environmental consequences.
The circular flow model shows money and resources moving between households and firms — and shows, by what it leaves out, why the environment gets forgotten.
Growth, GDP and the difference between them
Economic growth means an increase in the total market value of the goods and services a country produces over a given time period. GDP is how we put a figure on that total: the monetary value of everything produced within a country’s borders, usually over a year.
So GDP is the size of the economy and growth is the change in that size. GDP acts as an indicator of a country’s economic performance and productivity, and its year-on-year change is the standard measure of how well things are going.
Growth rate, year on year
growth rate (%) = (GDP this year − GDP last year) ÷ GDP last year × 100
A positive rate means expansion; a negative rate means contraction. If a country’s GDP grew by 2% in 2023 compared with the year before, that is a positive rate of growth for the period. The UK’s GDP grew by 7.5% in 2021, showing a sharp rise in activity after the disruption of the pandemic — a big number, but one that mostly reflects recovering ground lost the year before.
One thing worth adding here, because it catches people out: growth figures should be real, not just nominal. If every price in the country rose by 3% and nothing extra was actually made, GDP measured in cash would still look 3% bigger. Real GDP strips inflation out so you are measuring more stuff, not just bigger price tags.
Two ways to add it up
GDP can be measured from either end of the same transactions, which is a neat idea once it clicks.
Every pound spent by somebody is a pound earned by somebody else, so adding up the spending and adding up the earnings must land on the same place.
Per capita GDP
Total GDP tells you how big an economy is, not how well off the people in it are. A country with a huge population will naturally produce more in total. To compare living standards you need the average per person:
Average income per person
per capita GDP = GDP ÷ population
This makes comparisons far more meaningful. Switzerland has a much higher per capita GDP than Burundi, and that gap tells you something real about the two countries. But an average is only an average, and it says nothing about who actually holds the money.
Both countries would report the same per capita GDP. Four people out of five in country B would not recognise the description.
This is why per capita GDP is criticised for ignoring inequality in how income is actually distributed. Even within one country the average conceals a lot: the UK has a relatively high per capita GDP, yet income inequality remains a serious issue, with some regions living well below the national average.
The linear model and the circular flow
Economic growth is driven by the interaction of supply and demand, and it is usually treated as a measure of prosperity. The traditional approach to it follows a linear model: firms, industries and whole countries push production and consumption upwards without considering the environmental consequences. Waste, pollution and degradation are simply not part of the calculation.
The circular flow model is a simplified picture of how goods, services and money move between households and firms. Households supply factors of production — land, labour and capital — to businesses, and receive income in return. They spend that income on goods and services, which becomes revenue for firms, which pays for the next round of factors. Round it goes.
The model is a closed loop: nothing enters and nothing leaves. That is exactly the assumption the next page takes apart.
Examiners like this model because of what it leaves out. Nothing enters the loop and nothing leaves it, so the resources going in appear to come from nowhere and the waste coming out appears to go nowhere. Point that out in an answer and you have made an evaluation, not just a description.
The other awkward bit: GDP counts activity, not benefit. Cleaning up an oil spill adds to GDP. So does treating illness caused by pollution. A forest left standing adds nothing at all. GDP was never designed to measure wellbeing, and it does not.
Worked examples
WORKED EXAMPLE
A country’s GDP was 480 billion units in 2024 and 504 billion units in 2025. Its population is 12 million. Calculate the growth rate and the per capita GDP for 2025. [3]
Step 1: find the change in GDP504 − 480 = 24 billionStep 2: express it as a percentage of the starting value24 ÷ 480 × 100 = 5%Always divide by the earlier year, not the later one.Step 3: per capita GDP for 2025504 000 000 000 ÷ 12 000 000 = 42 000Growth rate 5%, per capita GDP 42 000 units
WORKED EXAMPLE
Explain why per capita GDP is a limited measure of living standards. [4]
Say what it is firstper capita GDP = GDP ÷ population
It is the average income per person, which does make comparison between countries easier.
Limitation 1: it is only an average
Two countries with the same figure can have completely different distributions. If a small group holds most of the income, most people live well below the average.
Limitation 2: it counts activity, not wellbeing
Spending on pollution cleanup or treating illness raises GDP, while unpaid work and a healthy environment add nothing to it.
Hides inequality; measures output rather than welfareTwo developed limitations beats four listed ones.
💡 Exam tip
Keep GDP and growth separate. GDP is the size, growth is the percentage change in that size. Questions often test the difference.
Learn both approaches by their components. Expenditure: consumption, government spending, investment, exports minus imports. Income: wages, rent, interest, profit.
Divide by the earlier year when calculating a growth rate. It is the single most common arithmetic slip in this topic.
Use the phrase “does not show distribution” when criticising per capita GDP. It is the point examiners are looking for.
Describe the circular flow by its two directions: factors and goods one way, money the other.
Have one country example ready for a comparison — Switzerland against Burundi does the job in a single sentence.
⚠️ Common mix-up
“Negative growth means the economy shrank to nothing.” It means GDP fell compared with last year. The economy is still there, just smaller.
Confusing GDP with income per person. A large country can have huge GDP and low per capita GDP at the same time.
Thinking rising GDP always means rising living standards. It depends on population, distribution and whether prices rose too.
Adding imports into the expenditure approach. Imports are subtracted, because they were produced somewhere else.
Muddling the linear model with the circular flow. The linear model is an approach to growth that ignores environmental consequences; the circular flow is a diagram of money and resources moving between households and firms.
Treating the circular flow as complete. It is a closed loop with no environment in it, and that omission is the point.
Up next: The Environmental Cost of Growth — what happens when you put the missing environment back into the circular flow, and whether growth can ever come apart from the damage it does.
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