Cambridge O Level Economics: Economic growth and recession (2281) – Revision Notes

These notes condense section 4.6 (Economic growth) of the Cambridge O Level Economics 2281 syllabus for 2026, part of topic 4, Government and the macroeconomy. Read the full study guide for explanations, then try the practice questions. Track your progress with the course hub and the printable checklist, and find gaps with the free diagnostics. The data below is made up for practice.

Key definitions (4.6.1 to 4.6.3)

• Economic growth: a rise over time in how much an economy produces, measured by the percentage rise in real GDP.
• GDP: the value of all goods and services made within a country’s borders over a period.
• Nominal GDP: GDP valued at current prices. It rises when prices rise.
• Real GDP: GDP valued at constant prices, so it tracks output only.
• GDP per head (per capita): real GDP divided by population.
• Recession: a fall in real GDP, often judged by the common rule of thumb of two quarters in a row of decline.
• Potential output: what the economy can produce when all its resources are fully used. The PPC shows it.

Formulas

Item	Formula
Real GDP	nominal GDP x 100 / price index
Growth rate (%)	change in real GDP / starting real GDP x 100
GDP per head	real GDP / population
Actual output as a share of potential	actual / potential x 100
Real GDP	number of workers x output per worker

Method: measuring growth in four steps

1. Convert each nominal figure to real GDP by dividing by the price index and multiplying by 100.
2. Work out the percentage change in real GDP between the years.
3. Divide real GDP by population to get GDP per head, then find its percentage change.
4. Comment: has output grown, and has the average person gained?

Worked reminder: Country F (invented)

Year	Nominal GDP	Price index	Real GDP	Population (millions)	Real GDP per head
1	840	120	700	8.0	87.50
2	924	132	700	8.1	86.42
3	990	150	660	8.2	80.49

Nominal GDP rose 10.0% in year 2 and 7.14% in year 3. Real GDP grew 0% in year 2 and fell 5.71% in year 3. Higher nominal GDP did not mean more output. If real GDP keeps falling in later years, the economy is in recession.

Recession (4.6.3)

• Causes: fall in consumer spending, in investment, or in exports; sharp cuts in government spending or rises in tax; higher interest rates; a banking crisis that stops lending; a supply shock such as a sharp rise in input costs.
• Chain of reasoning: demand falls, firms sell less, firms cut output and jobs, unemployment rises, incomes fall, demand falls again.
• Consequences: unemployment, lower incomes, business closures, lower tax revenue, higher benefit spending, a larger budget deficit, weaker inflation, lower investment, harm to trading partners.
• PPC: the economy moves to a point further inside the PPC. The PPC does not shift unless resources are destroyed.

Worked reminder: a recession in numbers

Country N is invented. Real GDP per quarter, in billions: quarter 1, 320; quarter 2, 316; quarter 3, 311; quarter 4, 313. Potential output is 330 and the tax rate is 25% of output.

• Quarter 2: (316 - 320) / 320 x 100 = -1.25%. Quarter 3: (311 - 316) / 316 x 100 = -1.58%. Two consecutive falls meets the rule of thumb, so the economy counts as having been in recession.
• Peak to trough: (311 - 320) / 320 x 100 = -2.81%.
• Share of potential: 96.97% in quarter 1 and 94.24% in quarter 3. The gap grew from 10 to 19.
• Tax revenue: 0.25 x 320 = 80.0 and 0.25 x 311 = 77.75, a fall of 2.25 a quarter.
• Quarter 4: (313 - 311) / 311 x 100 = +0.64%. Output has started to recover but is still below its earlier peak, so the gap to potential (17) remains large.

Chains of reasoning to learn

Write these as linked steps, not as separate facts.

1. Recession: fall in total demand, so firms sell less, so they cut output and jobs, so household incomes fall, so spending falls again.
2. Growth from idle resources: rise in demand, so firms hire the unemployed and use spare machines, so real GDP rises, so the economy moves toward the PPC.
3. Growth from capacity: investment or training, so output per worker rises, so potential output rises, so the PPC shifts right.
4. Benefit to the government: growth raises incomes, so tax revenue rises, so spending on health and schooling can rise without higher tax rates.
5. Cost to the environment: faster output uses more resources and energy, so pollution and depletion rise, so future living standards may fall.

Evaluation checklist for policy questions

Before you judge a policy, check each of these.

• Is there spare capacity? Demand policies work best when resources are idle.
• How long will it take? Education and infrastructure are slow. Interest rate changes take time to work through.
• Who pays, and what does it cost the budget?
• Are there side effects on prices, the trade balance or the environment?
• Which type of economy is it? A poor economy may lack the funds for large projects, while a rich economy may have little spare capacity.

End with a short judgement that follows from your points.

Causes of growth (4.6.4)

Type	What happens	Diagram in words
Rise in total demand	Idle resources are used and real GDP rises	Movement from a point inside the PPC toward the curve
Investment, technology, more or better factors of production	Capacity rises	The whole PPC shifts to the right (outward)

Quantity of factors: more workers, land, capital. Quality: skills, health, better machines. Technology: new methods raise output per worker.

Consequences of growth (4.6.5)

Benefits	Costs
Higher average incomes and living standards	Pollution and climate damage
Fewer people in poverty	Resource depletion
More jobs	Congestion and crowding
More tax revenue for health, education	Wider inequality if gains go to the better off
More profit for investment	Inflation and rising imports if demand grows too fast

Weighing: growth matters most in poorer economies, where basic needs are unmet. Environmental costs weigh more in richer economies. Always tie your answer to the type of economy in the question.

Policies and their effectiveness (4.6.6)

Policy	Effect	Main limit
Fiscal: more spending or lower taxes	Raises demand	Deficit; inflation if near full use of resources
Monetary: lower interest rates	Raises spending and investment	Time lag; weak if confidence is low
Education and training	Raises labour quality	Slow results
Infrastructure	Cuts firms’ costs	Costly, slow
Investment incentives	Raises investment	Depends on confidence
Trade policy, foreign investment	Brings in capital and technology	Competition for home firms

Evaluation prompts: spare capacity, time lag, cost, side effects on prices and the trade balance, and the type of economy.

Must-know distinctions

• Real versus nominal: only real GDP measures growth.
• Total versus per head: growth in total GDP can hide a fall in GDP per head if population grows faster.
• Movement toward the PPC versus shift of the PPC: the first is short-run use of idle resources, the second is a rise in capacity.
• Recession versus slower growth: in a recession real GDP falls. In slower growth it still rises, but more slowly.

Quick self-test

1. Nominal GDP is 900 and the price index is 125. Find real GDP.
2. Real GDP rises from 480 to 504. Find the growth rate.
3. Real GDP is 480 with population 12.0 million, then 504 with population 12.6 million. How does GDP per head change?
4. Nominal GDP rises by 8% while prices rise by 5%. Find real growth.
5. Actual output is 171 and potential output is 190. Find actual output as a percentage of potential, and the gap.
6. Output falls by 40 in a recession. The tax rate is 30% of output. By how much does tax revenue fall?
7. Employment rises 2.0% and output per worker rises 2.5%. Find the growth in real GDP.
8. Real GDP rises 2.4% and population 1.6%. Find the change in GDP per head.
9. Real GDP falls 3% in one year and 2% the next. Find the total change.
10. Explain the difference between a movement toward the PPC and a shift of the PPC.

Answers

1. 900 / 125 x 100 = 720.
2. (504 - 480) / 480 x 100 = 5.0%.
3. 480 / 12.0 = 40.0 and 504 / 12.6 = 40.0, so GDP per head is unchanged (0% growth), although total GDP rose.
4. 1.08 / 1.05 - 1 = +2.86%.
5. 171 / 190 x 100 = 90%; the gap is 19.
6. 40 x 0.30 = 12.
7. 1.02 x 1.025 - 1 = 4.55%.
8. 1.024 / 1.016 - 1 = +0.79%.
9. 0.97 x 0.98 - 1 = -4.94% (not -5%, because the second fall is on a smaller base).
10. A movement toward the PPC uses idle resources and needs no extra capacity. A shift of the PPC means capacity has risen, through investment, technology or more or better factors of production.

Where marks are usually lost

• Calling nominal GDP growth “economic growth” without deflating.
• Dividing by the new figure instead of the old figure when finding a percentage change.
• Adding percentage falls (3% and 2%) instead of compounding them.
• Forgetting to divide by population when asked for GDP per head.
• Drawing a recession as an inward shift of the PPC.
• Writing “growth is good” or “growth is bad” with no reference to the economy in the question.
• Listing policies without saying how well they work or what holds them back.
• Giving a cause of recession without the chain of events that follows from it.

Official syllabus

Cambridge O Level Economics 2281, syllabus for examination in 2026 (version 2), published by Cambridge University Press & Assessment (Cambridge International), section 4.6.