Market failure—asymmetric information

· Asymmetric information = a situation where one party in a market transaction knows more than the other.
· This creates market failure because decisions are made using unequal information, so resources may be allocated inefficiently.
· Focus on two core problems: adverse selection and moral hazard.
· Typical exam line: asymmetric information can cause misallocation of resources, welfare loss, and a market outcome that is not socially efficient.

Adverse selection

· Adverse selection = hidden information before the transaction. One side cannot accurately tell the type, quality, or risk level of the other side.
· This means the uninformed side may offer a price based on average quality/risk, not true quality.
· As a result, high-quality / low-risk participants may leave the market, while low-quality / high-risk participants remain.
· Classic example: used car market (“lemons”) — buyers cannot distinguish good cars from bad cars, so they offer a lower average price; sellers of good cars exit the market.
· Insurance example: people who know they are high risk are more likely to buy insurance, pushing up premiums.

Moral hazard

· Moral hazard = hidden action after the transaction. One side changes behaviour because they do not bear the full cost of their actions.
· Most often applied to insurance markets: once insured, people or firms may behave in a riskier or less careful way.
· This raises the insurer’s expected payouts and can increase costs for everyone in the market.
· Example: an insured driver may take fewer precautions; a business with insurance may invest less in loss prevention than it otherwise would.
· Key distinction: adverse selection happens before exchange; moral hazard happens after exchange.

How market failure happens

· When buyers or sellers cannot observe important information, price signals become unreliable.
· The market may produce the wrong quantity, trade the wrong quality, or attract the wrong participants.
· Good-quality goods, low-risk consumers, or trustworthy sellers may be crowded out.
· The result is allocative inefficiency because market outcomes no longer reflect true costs, benefits, and risks.
· In evaluation, link asymmetric information to reduced market efficiency, welfare loss, and possible under-provision or market shrinkage/collapse.

Responses to asymmetric information: government responses

· Legislation and regulation can require disclosure, set minimum standards, and punish misleading behaviour.
· Examples: consumer protection laws, truth-in-advertising rules, mandatory information disclosure, licensing, and financial regulation.
· Provision of information by government reduces information gaps, for example through safety labels, inspections, standardized reporting, or public awareness campaigns.
· Stronger information rules can improve consumer confidence and reduce welfare loss.
· In evaluation, mention that regulation may be costly, imperfectly enforced, or create administrative burdens.

Responses to asymmetric information: private responses

· Signalling = the informed side sends a credible signal about quality or risk.
· Examples of signalling: warranties, guarantees, brand reputation, qualifications, certification, inspection records.
· Screening = the uninformed side takes action to gather information and sort participants by quality or risk.
· Examples of screening: job interviews, background checks, insurance questionnaires, medical checks, credit checks, trial periods.
· Best exam move: explain that both signalling and screening aim to reduce the information gap so markets work more efficiently.

Evaluation points

· Government intervention can reduce information failure, but success depends on accuracy of information, monitoring, and enforcement.
· Private solutions may work well where reputation matters and signals are credible, but weak signals may be ignored or faked.
· Some policies improve efficiency but may increase costs for firms or consumers.
· Information provision helps only if consumers can understand and use the information.
· Strong evaluation often compares government regulation with market-based/private responses.

Fast exam structure

· 1. Define the key concept.
· 2. Use an example that fits the concept exactly.
· 3. Explain the information gap and how it changes incentives or behaviour.
· 4. Show the result: inefficient outcome, reduced market efficiency, welfare loss, or market shrinkage.
· 5. Evaluate a response with at least one strength and one limitation.