Key Idea: Topic 2.9 explains why the market completely fails to provide public goods, and why government must step in. This is the most extreme form of market failure — zero private provision.
✅ Core definitions
- Public good
- Non-rivalrous (one person's use doesn't reduce availability) AND non-excludable (cannot prevent non-payers from using it).
- Free-rider problem
- No one pays → no private firm produces → complete market failure.
- Quasi-public good
- Partially rivalrous or excludable (roads, parks, Wi-Fi). Can be provided privately with some excludability.
📊 The goods matrix (must-know)
- Private goods — rivalrous + excludable (food, clothing)
- Public goods — non-rivalrous + non-excludable (national defence, street lighting)
- Common pool resources — rivalrous + non-excludable (fisheries, forests)
- Club goods (quasi-public) — non-rivalrous + excludable (cinemas, toll roads, streaming services)
Learn the 2×2 matrix: rows = rivalrous/non-rivalrous, columns = excludable/non-excludable. Be ready to classify any good.
🏛️ Government provision
- Government funds public goods through taxation
- Provision ≠ production — government can hire private firms to build/deliver
- Cost-benefit analysis used to decide which public goods to provide
- Technology can change classification: roads were non-excludable → toll technology makes them excludable
⚖️ Evaluation
✅ Pros: Solves free-rider problem. Ensures essential goods exist. Benefits everyone equally.
❌ Cons: No price signal → hard to know optimal quantity. Government failure risk (over/under-provision). Opportunity cost of taxation.
The key distinction: externalities cause under-provision. Public goods cause zero provision. This is why public goods are a more complete market failure.