SACE Economics — Stage 2
Market Failure — SACE Economics — Stage 2 Flashcards & Quiz
Market failure occurs when the free market fails to allocate resources efficiently. For SACE Economics Stage 2 you need to explain the main causes — externalities, public goods, information asymmetry, and market power — and evaluate the government responses used to correct them. Strong responses use diagrams (externality wedge, MSB/MSC curves) and link Australian examples like carbon pricing, public health campaigns and ACCC regulation.
Key Points
- Negative externality: social cost exceeds private cost (e.g. pollution). Optimal output is where MSB = MSC, not MPB = MPC.
- Positive externality: social benefit exceeds private benefit (e.g. vaccination, education). Markets under-supply.
- Public goods are non-rival and non-excludable (defence, street lighting). Free-rider problem means private markets under-supply them.
- Information asymmetry: one party knows more (used cars, insurance). Leads to adverse selection and moral hazard.
- Government responses: taxes/subsidies, regulation, direct provision, information campaigns, tradeable permits.
- Diagram: externality wedge between MSB and MSC identifies deadweight loss and optimal intervention.
Common Mistakes to Avoid
- Confusing public goods with merit goods — merit goods are under-consumed due to imperfect info, not non-rivalry.
- Calling any monopoly a "market failure" without linking it to allocative inefficiency.
- Forgetting government failure — intervention can itself be inefficient (regulatory capture, red tape).
- Treating externalities as always negative — positive externalities also justify intervention (subsidies).
- Drawing externality diagrams without labelling the social optimum and deadweight loss.
Exam Strategy
SACE market failure questions usually ask you to identify a failure, recommend a policy and evaluate it. Method: (1) define market failure and classify it (externality, public good, asymmetry, market power), (2) draw the externality or MSB/MSC diagram, (3) propose a specific policy with a real example, (4) evaluate effectiveness, efficiency, equity and unintended consequences, (5) conclude with a reasoned judgement on whether the cure is worth the cost.
Sample Flashcards
Q1: Summarise the economic rationale for government intervention in markets.
Government intervention is justified when markets fail to achieve allocatively efficient outcomes. The market failures in the SACE outline are: (1) undersupply of public goods — non-rival and non-excludable, so the free-rider problem stops private provision, (2) uncompetitive markets — monopoly or oligopoly power leads to P > MC and deadweight loss, (3) externalities — positive and negative, in production and consumption, (4) asymmetric information — adverse selection and moral hazard. Measures include regulation, taxes, subsidies and advertising. Governments also redistribute income when market outcomes are judged inequitable. Because intervention can have unintended consequences, it must be evaluated, not assumed to work.
Q2: Evaluate regulation, taxes, subsidies and advertising as measures to correct market failure.
Regulation (bans, standards, licensing) directly limits a harmful activity — effective when the harm is severe, but costly to enforce and inflexible. Taxes on goods with negative externalities raise price toward marginal social cost, cut quantity and raise revenue, but the right tax is hard to calculate and some taxes are regressive. Subsidies lower costs for goods with positive externalities and raise quantity toward the social optimum, but cost taxpayers and may reward consumption that would have happened anyway. Advertising and information campaigns correct information problems at low cost, but results are slow and uncertain. Judge each measure by how much it reduces deadweight loss, what it costs, and its unintended consequences.
Sample Quiz Questions
Q1: Information asymmetry is a type of market failure that can justify government intervention.
Answer: TRUE
Information asymmetry (one party has more information than the other) leads to adverse selection and moral hazard, causing markets to function inefficiently. Government can intervene through disclosure requirements, consumer protection laws, and regulation.
Q2: A tax on a good with a negative externality can move output toward the socially optimal quantity.
Answer: TRUE
The tax raises the producer’s private cost toward the marginal social cost, shifting supply left. Price rises and quantity falls toward the social optimum, reducing the deadweight loss caused by overproduction.
Revision Tip
Market failure vocabulary plus the externality diagram are high-yield recall — drill a Revizi deck on each failure type and sketch the diagrams from memory for exam-speed recall.
Related Concepts
Last updated: 9 October 2026 · 2 sample flashcards · 2 sample quiz questions