Scarcity, choice and opportunity cost
Scarcity, choice and opportunity cost: build the core model, apply it to evidence and qualify conclusions where outcomes depend on context.
9708 section 1.1; AS Level. Checked against Cambridge's 2026–2028 Version 2 (latest version published December 2025) and 2029 Version 1 (published September 2026). Cambridge states that neither version has significant changes affecting teaching. Always follow the syllabus for the candidate's examination year.
Before you begin
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What does opportunity cost measure?
What you will learn
- Explain scarcity and choice at individual, firm and government level
- Define opportunity cost as the next-best alternative forgone
- Apply what, how and for whom to produce
Core model and terms
Scarcity exists because resources are limited relative to wants. Consumers, firms and governments therefore choose how to use time, income, labour, land and capital; a resource need not be rare to be scarce in a particular use.
Apply and evaluate
Opportunity cost is the benefit of the next-best feasible alternative forgone. Resource allocation answers what to produce, how to produce it and who receives the output. Name the decision-maker and the constraint before identifying the forgone option.
Pause and explain
Which statement best applies scarcity, choice and opportunity cost?
Worked example
A council funds a bus route instead of the next-ranked road project. Identify its opportunity cost.
Show the worked solution
- Name the fixed budget
- Compare feasible projects
- The expected benefit of the road project is forgone
Answer Name the fixed budget → Compare feasible projects → The expected benefit of the road project is forgone
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A council funds a bus route instead of the next-ranked road project. Identify its opportunity cost.
Give me a hint
Identify the relevant idea in scarcity, choice and opportunity cost, then trace the economic chain.
Compare my reasoning
- Name the fixed budget
- Compare feasible projects
- The expected benefit of the road project is forgone
Name the fixed budget Compare feasible projects The expected benefit of the road project is forgone
Look for these in your work
- Name the fixed budget
- Compare feasible projects
- The expected benefit of the road project is forgone
A student uses two evening hours for paid work rather than revision. Explain the opportunity cost.
Give me a hint
Identify the next-best feasible use of the same time.
Compare my reasoning
- Time is scarce
- Revision is the next-best alternative
- Its expected learning benefit is forgone
Time is scarce Revision is the next-best alternative Its expected learning benefit is forgone
Look for these in your work
- Time is scarce
- Revision is the next-best alternative
- Its expected learning benefit is forgone
A firm buys a machine instead of hiring another worker. State the allocation questions it faces.
Give me a hint
Apply the three questions to the firm’s decision.
Compare my reasoning
- What: machine-made output
- How: capital-intensive production
- For whom: customers able and willing to buy
What: machine-made output How: capital-intensive production For whom: customers able and willing to buy
Look for these in your work
- What: machine-made output
- How: capital-intensive production
- For whom: customers able and willing to buy
A government has funds for either flood defences or a clinic. Explain why the clinic is not automatically the opportunity cost.
Give me a hint
Check feasibility and ranking before naming the alternative.
Compare my reasoning
- Both projects must be feasible
- Rank the rejected options
- Only the next-best forgone project is the opportunity cost
Both projects must be feasible Rank the rejected options Only the next-best forgone project is the opportunity cost
Look for these in your work
- Both projects must be feasible
- Rank the rejected options
- Only the next-best forgone project is the opportunity cost
Common mistakes
- Calling the chosen option’s price its opportunity cost without identifying what is forgone.
What can you explain now?
What does opportunity cost measure?
Compare with the explanation
The benefit of the next-best feasible alternative forgone
It measures the most valuable feasible alternative given up, not all rejected choices.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Before moving on, explain the central idea in scarcity, choice and opportunity cost and state one condition that could change its effect.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.