1.6 Classification of goods and services
- Syllabus
- 9708–2026–2027
- Topic
- 1.6
- Level
- AS
Learning objectives
1.6.1Free and private goods• Nature and definition of free goods and private goods (economic goods)1.6.2Public goods• Nature and definition of public goods1.6.3Merit goods• Nature and definition of merit goods: under-consumption as a result of imperfect information in the market1.6.4Demerit goods• Nature and definition of demerit goods: over-consumption as a result of imperfect information in the market
Free goods and private economic goods
A free good is available in sufficient quantity that using it has no opportunity cost. A private or economic good is scarce, so producing or consuming it uses resources that have an alternative use.
| Feature | Free good | Private economic good |
|---|---|---|
| Scarcity | Not scarce in that context | Scarce relative to wants |
| Opportunity cost | None for an additional use | Positive |
| Rivalry | Normally no meaningful reduction for another user | One person's consumption normally leaves less for others |
| Exclusion | Access is normally not worth restricting | Ownership or price can normally restrict access |
| Example | Sunlight in an open field | A loaf of bread |
Classification can change with context and technology. Ordinary air may be a free good in the countryside, while purified oxygen in a cylinder is scarce and requires resources to supply.
A zero money price does not make a good free in the economic sense. Food given as a gift and healthcare free at the point of use still have opportunity costs because scarce resources produced them.
Public goods are non-rival and non-excludable
A public good is non-rival: one person’s use does not substantially reduce another’s, and non-excludable: it is difficult to prevent non-payers from benefiting.
These properties create a free-rider problem, because individuals can wait for others to pay. Governments or collective arrangements may therefore provide the good, though congestion can make rivalry change at the margin.
A lighthouse signal can guide many ships at once and is difficult to withhold from a non-paying ship; national defence has similar properties.
Public does not mean government-produced and free does not mean no resource cost; the classification concerns rivalry and exclusion.
Merit goods may be under-consumed because consumers lack information
A merit good creates benefits that consumers may undervalue, so imperfect information can lead to under-consumption relative to the socially desirable level.
The market outcome reflects perceived private benefit, while education or vaccination may also create wider benefits. Policy can improve information, subsidise use or provide the good directly.
People may delay preventive health checks because they underestimate future benefits; reminders, information and subsidised access can increase uptake.
Calling a good merit does not mean every person must consume more; the economic issue is systematic information and welfare divergence.
Demerit goods may be over-consumed because consumers lack information
A demerit good is consumed above the socially desirable level when consumers underestimate its harmful effects, often because information is imperfect or addictive behaviour distorts choice.
The market quantity reflects perceived private benefit and cost; education, regulation, taxation or age restrictions may reduce the gap, with trade-offs for liberty and enforcement.
A consumer may underestimate the long-run health cost of cigarettes, so an information campaign and excise tax can reduce consumption, though neither guarantees the socially optimal quantity.
A demerit good is not defined by being illegal or disliked; the key is systematic over-consumption relative to welfare.