This revision replaces the earlier Topic 1.6 draft. It is aligned to the 2026–2028 syllabus and deliberately removes consumer-goods/capital-goods classification, which is not one of the four current Topic 1.6 requirements.
Exact syllabus coverage
- 1.6.1 nature and definition of free goods and private goods (economic
goods);
- 1.6.2 nature and definition of public goods;
- 1.6.3 nature and definition of merit goods: under-consumption resulting
from imperfect information in the market;
- 1.6.4 nature and definition of demerit goods: over-consumption resulting
from imperfect information in the market.
Product mastery map
The portal tracks six skills:
- distinguish free goods from private/economic goods;
- explain rivalry and excludability as characteristics of private goods;
- define public goods using non-rivalry and non-excludability;
- explain merit-good under-consumption through imperfect information;
- explain demerit-good over-consumption through imperfect information;
- classify unfamiliar examples while recognising that categories can overlap.
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1. The classification framework
Economists classify goods because different characteristics produce different market outcomes.
The four syllabus categories do not form one single mutually exclusive list. They answer different questions:
| Classification | Main question |
|---|---|
| Free or economic/private? | Is the good scarce and does it have an opportunity cost? |
| Private or public? | Is consumption rival and can non-payers be excluded? |
| Merit or demerit? | Does imperfect information cause too little or too much consumption? |
This means one product may fit more than one category.
Example:
- a cigarette is an economic/private good because it is scarce;
- it is also a demerit good because imperfect information may lead to
over-consumption.
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2. Free goods
Definition
A free good is available in sufficient abundance relative to demand and has no opportunity cost.
Using more of it does not require society to sacrifice another valued use of scarce resources.
Examples
Possible examples in ordinary conditions include:
- sunlight;
- air in an unpolluted outdoor environment;
- seawater at the coast.
Examples must be contextual. Air delivered in an oxygen cylinder is not a free good because labour, equipment and storage resources are required.
Price is not the decisive test
A product is not automatically a free good merely because the user pays no direct price.
A publicly funded hospital appointment is free at the point of use, but it is an economic good because doctors, buildings and equipment are scarce.
Examination chain
abundant relative to demand → no scarcity at the point of use → no<br>opportunity cost → free good.
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3. Private goods or economic goods
Cambridge terminology
The current syllabus uses the phrase private goods (economic goods). The core contrast with free goods is scarcity.
Definition
An economic or private good is scarce relative to demand and therefore has an opportunity cost.
Resources used to produce or consume it could have been used elsewhere.
Usual additional characteristics
Private goods are also normally:
- rival in consumption;
- excludable.
Rivalry
One person's consumption reduces the quantity available to somebody else.
If one person eats a particular loaf of bread, the same loaf cannot be eaten by another person.
Excludability
People can be prevented from consuming the product, usually through ownership, a price or an access rule.
A cinema can refuse entry to somebody without a ticket.
Examples
- food;
- clothing;
- housing;
- transport tickets;
- medical appointments;
- electricity.
Opportunity-cost chain
resources are scarce → choosing this product sacrifices another use → the<br>good has an opportunity cost → it is an economic/private good.
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4. Free goods versus products free at the point of use
This distinction is frequently tested.
| Item | Direct price to user? | Scarce resources used? | Classification |
|---|---|---|---|
| Sunlight in ordinary conditions | No | No meaningful scarce production resources | Free good |
| State-school lesson | Often no | Yes: teachers, buildings and equipment | Economic good |
| Public park visit | Often no | Yes: land and maintenance | Economic good |
| Oxygen in a hospital | May be no | Yes: production, storage and delivery | Economic good |
The existence of government finance does not remove opportunity cost.
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5. Public goods
Definition
A pure public good is:
- non-rival; and
- non-excludable.
Both characteristics are required.
Non-rivalry
One person's benefit does not significantly reduce the benefit available to another person.
Example:
One resident receiving protection from national defence does not significantly reduce the protection received by other residents.
Non-excludability
It is difficult or impossible to prevent non-payers from benefiting.
Example:
Once a flood defence protects an area, households inside the protected area benefit even if they did not voluntarily pay.
Standard examples
- national defence;
- street lighting;
- flood defences;
- some lighthouse services.
The free-rider problem
Non-excludability creates an incentive to benefit without paying.
non-payers cannot easily be excluded → consumers may conceal willingness to<br>pay → private revenue is difficult to collect → the market may not provide the<br>good.
This market-provision problem is developed further in Topic 3.1.
Government provision is not the definition
A good is public because of non-rivalry and non-excludability, not because the government provides it.
State education and healthcare are normally not pure public goods because:
- access can be restricted;
- places, staff time and equipment are limited;
- one additional user can reduce availability for others.
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6. Pure and impure public goods
Real examples may change characteristics with congestion or technology.
Congestible goods
A road may be approximately non-rival when empty but rival when congested.
Excludable collective services
A road can become excludable when electronic tolling is introduced.
Examination approach
Do not memorise a label without explanation. Apply the tests:
- Does one person's use reduce availability for others?
- Can non-payers be excluded?
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7. Merit goods
Definition
A merit good is under-consumed in a free market because consumers have imperfect information and underestimate its benefits.
Core syllabus chain
consumers lack or misunderstand information → private benefit is<br>underestimated → demand is lower than it would be with full information → the<br>good is under-consumed.
Examples
- education;
- preventive healthcare;
- vaccinations;
- health screening;
- safety equipment.
What consumers may misunderstand
Consumers may underestimate:
- future income benefits from education;
- the probability or severity of illness;
- long-term health gains;
- the effectiveness of prevention;
- risks created by delaying treatment.
Under-consumption
Under-consumption does not mean nobody consumes the good. It means the market quantity is below the level that would be chosen if consumers were fully informed.
Important boundary
Low income can also limit access in the real world, and external benefits may strengthen the case for intervention. However, the defining explanation required in current Topic 1.6 is imperfect information.
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8. Demerit goods
Definition
A demerit good is over-consumed in a free market because consumers have imperfect information and underestimate its costs or risks.
Core syllabus chain
consumers lack or misunderstand information → private cost is underestimated<br>→ demand is higher than it would be with full information → the good is<br>over-consumed.
Examples
- cigarettes;
- alcohol;
- gambling services;
- highly harmful addictive products.
What consumers may misunderstand
Consumers may underestimate:
- health risks;
- addiction probability;
- long-term financial cost;
- effects on future productivity and income;
- difficulty of stopping consumption.
Over-consumption
Over-consumption means the market quantity exceeds the amount that would be chosen if consumers possessed and processed accurate information.
Important boundary
External costs may strengthen the case for intervention, but externality analysis belongs mainly to A Level Topics 7.3–7.4. The AS definition here focuses on imperfect information.
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9. Merit goods versus public goods
These terms are not interchangeable.
| Merit good | Public good |
|---|---|
| Defined by under-consumption caused by imperfect information | Defined by non-rivalry and non-excludability |
| May be rival and excludable | Pure form is non-rival and non-excludable |
| Example: education | Example: national defence |
Education is normally a merit good but not a pure public good because school places and teacher time are limited and access can be controlled.
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10. Demerit goods versus private goods
A demerit good is often also a private/economic good.
Example: cigarettes
- scarce and produced with resources → economic/private good;
- individual packets are rival and excludable → private-good characteristics;
- costs may be underestimated → demerit good.
The classifications overlap because they describe different features.
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11. Imperfect information
Meaning
Imperfect information exists when consumers do not possess, understand or correctly process all relevant information needed for a decision.
Possible causes include:
- technical or complex information;
- uncertain future effects;
- misleading advertising;
- hidden product characteristics;
- limited financial or health literacy;
- rapidly changing evidence.
Imperfect information is not irrationality by itself
A consumer may make a rational decision using the information available, but the outcome can still differ from the fully informed choice.
Information and preference
Do not assume that every informed consumer will make the same choice. People can value risks and benefits differently. The economic issue is whether missing or misunderstood information systematically changes consumption.
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12. Classification decision tree
Step 1: Scarcity
Is the item scarce relative to demand and does using it involve an opportunity cost?
- no → free good;
- yes → economic/private good.
Step 2: Consumption characteristics
- rival and excludable → private-good characteristics;
- non-rival and non-excludable → public good.
Step 3: Information outcome
- imperfect information causes too little consumption → merit good;
- imperfect information causes too much consumption → demerit good.
Step 4: Explain overlap
State all classifications that are relevant and explain the criterion for each.
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13. Common examination traps
- Free of charge = free good. Wrong: opportunity cost is the test.
- Government-provided = public good. Wrong: use rivalry and excludability.
- Merit good = public good. Wrong: the definitions use different criteria.
- Demerit good = illegal good. Wrong: many demerit goods are legal.
- Public goods have no opportunity cost. Wrong: they use scarce resources.
- One category only. Wrong: classifications can overlap.
- Merit goods are under-consumed only because they are expensive. The current
syllabus definition requires imperfect information.
- Demerit goods are over-consumed only because of external costs. Topic 1.6
focuses on imperfect information.
- Non-rival means equally valued. It means one person's use does not reduce
another's available benefit.
- Non-excludable means zero price. It means access cannot easily be denied.
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14. Paper 1 method
When classifying an example:
- identify the criterion being tested;
- apply the criterion to the context;
- reject answers that confuse price with scarcity;
- reject answers that confuse government provision with public-good status;
- check whether the question asks about information and consumption.
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15. Paper 2 response templates
Explain why a public good may not be privately provided
A public good is non-rival and non-excludable. Since non-payers cannot easily<br>be excluded, consumers may free ride rather than reveal their willingness to<br>pay. A private firm may therefore be unable to collect sufficient revenue, so<br>the good may not be provided by the market.
Explain why education may be a merit good
Education may be under-consumed because consumers possess imperfect<br>information and underestimate its future private benefits. Demand is therefore<br>lower than it would be with full information, so the market quantity is below<br>the fully informed level.
Explain why cigarettes may be a demerit good
Cigarettes may be over-consumed because consumers possess imperfect<br>information and underestimate health risks, addiction and future costs. Demand<br>is therefore higher than it would be with full information.
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16. One-minute revision
- Free good: abundant relative to demand; no opportunity cost.
- Private/economic good: scarce; has opportunity cost; normally rival and
excludable.
- Public good: non-rival and non-excludable.
- Merit good: imperfect information causes under-consumption.
- Demerit good: imperfect information causes over-consumption.
Always state the criterion and apply it. A label alone is not enough.