Market failure: public goods

A good that is both NON-RIVALROUS (one person's consumption does not reduce availability for others) and NON-EXCLUDABLE (it is impossible to prevent anyone from using it). Examples: national defence, street lighting, lighthouses.

1) Private goods: excludable + rivalrous (food, clothing). 2) Public goods: non-excludable + non-rivalrous (national defence). 3) Common pool resources: non-excludable + rivalrous (fish stocks). 4) Club goods: excludable + non-rivalrous (Netflix, toll roads).

When individuals can benefit from a good without paying for it, removing the incentive for any private firm to supply it. Because non-payers cannot be excluded, rational consumers have no reason to pay voluntarily, so the good is not produced at all.

If everyone free-rides, no firm can cover its costs → the good is not produced at all. This is different from externalities, where the market under-provides. With public goods, the market provides ZERO — a complete market failure.

One person consuming the good does NOT reduce the amount available for others. A lighthouse beam doesn't get dimmer as more ships use it. Street lighting illuminates the road for everyone equally. This contrasts with private goods (eating a sandwich means no one else can).

Private goods: markets generally work well. Public goods: complete market failure (free-rider problem). Common pool resources: over-exploitation (tragedy of the commons). Club goods: can be provided privately, but may still involve under-provision if externalities exist.

A private company tries to sell national defence. You refuse to pay — but you're still protected because the army can't exclude you. Your neighbour also refuses. If everyone acts rationally, the company earns nothing and cannot fund a military — so no defence is provided.

It is impossible or impractical to prevent people from using the good, even if they don't pay. Everyone within a country benefits from national defence regardless of whether they pay taxes. A private firm cannot restrict access to charge a price.

Fish stocks are NON-EXCLUDABLE (anyone can fish in open waters) but RIVALROUS (every fish caught reduces the stock for others). Public goods must be both non-excludable AND non-rivalrous. The rivalry dimension makes fish a CPR, prone to over-exploitation.

Private goods are RIVALROUS (if you eat it, no one else can) and EXCLUDABLE (the shop can refuse to sell it). Public goods are the opposite on both dimensions — non-rivalrous and non-excludable. Markets work well for private goods but fail completely for public goods.

A club good is EXCLUDABLE (non-payers can be prevented from using it) but NON-RIVALROUS (consumption by one person does not reduce availability). Examples: Netflix (password required, but your watching doesn't reduce others' ability to watch), toll roads (pay to enter, but uncongested roads serve everyone equally).

Externalities cause under-provision — the market produces some but not enough (Qm < Q*). The free-rider problem causes ZERO provision — the good has clear social value but no private supply at all. Public goods represent a more extreme form of market failure.

Government provision funded through TAXATION. Since the government can compel everyone to pay taxes, no one can free-ride. The government then provides public goods (defence, street lighting, flood barriers) that benefit the whole population.

1) National defence — protects everyone in the country. 2) Street lighting — illuminates for all passers-by. 3) Flood barriers — protect an entire area. 4) Public fireworks displays — visible to everyone in range. All are non-rivalrous and non-excludable.

Examiners may give you a good and ask you to classify it. Draw or describe the matrix. Identify the two characteristics (rivalry, excludability) and place the good. Then explain the associated market failure and possible government response. This is a common short-answer question.

Because the free-rider problem means private firms cannot cover costs — no one would pay voluntarily. The government funds provision through TAXATION, which compels everyone to contribute. This ensures the good is produced despite the inability to charge a market price.

A good that has SOME characteristics of a public good but is not purely non-rivalrous or non-excludable. Technology or policy can make it partially excludable (e.g. toll roads) or it may become rivalrous under certain conditions (e.g. congested roads).

1) Solves the free-rider problem — everyone pays through taxation. 2) Ensures essential goods are available (defence, law enforcement, street lighting). 3) Can internalise positive externalities (e.g. public health benefits of clean water systems).

Through cost-benefit analysis (CBA) — estimating social benefits and social costs. There is no market price to guide allocation, so the government must estimate willingness to pay. This is imprecise and political factors (e.g. geopolitical priorities for defence) also influence decisions.

1) No price mechanism → hard to know optimal quantity (risk of over/under-provision). 2) Government failure: political motives, bureaucratic inefficiency, corruption. 3) Opportunity cost — funds could be used elsewhere. 4) Taxpayers may disagree on priorities.

1) Roads — generally non-rivalrous (at low traffic) but toll technology can make them excludable; they become rivalrous during congestion. 2) Parks — open access but rivalrous when overcrowded. 3) Wi-Fi — password makes it excludable; bandwidth congestion makes it rivalrous.

When government intervention leads to a worse outcome than the market failure it tries to fix. Causes include: political motives (spending on vote-winning projects rather than high-value ones), bureaucratic inefficiency, corruption, and lack of information about true social benefits.

Technology can make previously non-excludable goods excludable. Toll road technology makes roads excludable. Streaming passwords make digital content excludable. This means the boundary between public and private goods is blurred and changes over time.

No. Government provision means the government FUNDS the good through taxes. The actual production may be contracted to private firms. For example, the government pays a construction company to build a road, or a defence contractor to build military equipment.

Without a market price, the government cannot use price signals to determine optimal quantity. It must estimate demand through CBA, surveys, or political judgement. This creates a risk of over-provision (wasteful spending) or under-provision (insufficient services).

Every dollar spent on one public good cannot be spent on another. Spending more on defence means less for education or healthcare. Governments face trade-offs and must prioritise, which is inherently a political and normative decision.

It depends. If exclusion is practical, the market can provide (toll roads, streaming services). If the good generates positive externalities (parks improve mental health), government funding may be justified even when exclusion is possible. Mixed provision is common.

Weigh BOTH sides: advantages (solves free-riding, ensures essentials) vs disadvantages (government failure, opportunity cost, no price signals). Consider whether market-based alternatives exist (e.g. technology making the good excludable). Conclude with a balanced judgement.

It shows sophisticated understanding. Rather than classifying goods as strictly public or private, you can argue the boundary is blurred and depends on technology, congestion, and policy choices. This demonstrates nuance — examiners reward this in evaluation.

Defence spending varies enormously between countries based on geopolitical threats, not just economic analysis. The US spends ~3.5% of GDP on defence; Costa Rica has no military at all. These decisions reflect political values and security concerns, not just cost-benefit analysis.