Market failure
| English | Chinese | Pinyin |
|---|---|---|
| market failure | 市场失灵 | shì chǎng shī líng |
| merit goods | 有益物品 | yǒu yì wù pǐn |
| demerit goods | 有害物品 | yǒu hài wù pǐn |
| externality | 外部性 | wài bù xìng |
| third party | 第三方 | dì sān fāng |
| negative externality | 负外部性 | fù wài bù xìng |
| positive externality | 正外部性 | zhèng wài bù xìng |
| public goods | 公共物品 | gōng gòng wù pǐn |
| monopoly | 垄断 | lǒng duàn |
When markets get it wrong
- A factory makes cheap goods but pumps smoke over a town. The price tag never mentions the dirty air.
- That gap — costs the market ignores — is market failure 市场失灵.
Market failure occurs when:
It is an inefficient allocation — too much or too little is produced.
What market failure is
- Market failure = when a free market allocates resources inefficiently — too much or too little is produced.
- The market's prices don't capture the full costs or benefits to society.

Merit goods 有益物品 are under-consumed and demerit goods 有害物品 over-consumed, because of information failure
Demand & supply
Market failure: the free-market crossing isn't always best for society.
Air pollution from a factory is an example of a:
It imposes a cost on third parties — a negative externality.
Education creates a positive externality, benefiting society beyond the student.
A more educated workforce benefits everyone — a positive externality.
Externalities
- An externality 外部性 is a cost or benefit that falls on a third party 第三方 not involved in the trade.
- Negative externality 负外部性: pollution, congestion. Positive externality 正外部性: education, vaccination.

With a negative externality, true social cost lies above private cost, so the market over-produces.
A good with a negative externality tends to be:
The market ignores the external cost, so it makes too much.
Street lighting, which markets under-provide, is an example of a ______ good.
Public goods are non-excludable, so markets under-provide them.
Other types of market failure
- Public goods 公共物品 (street lighting, defence) — markets under-provide them; no one will pay for what they can get free.

A private good is rival and excludable, so firms supply it; a public good is neither, so the market under-provides it
- Merit / demerit goods, monopoly 垄断 power, and missing information all cause failure too.
Over- and under-production both count. Negative externalities → the market makes too much; positive externalities and public goods → it makes too little. Both are failures.
You've got it
- market failure = inefficient allocation; prices miss true social costs/benefits
- a negative externality (pollution) → over-production; a positive one → under-production
- public goods and monopoly are further sources of failure