Information failure

Why information matters

1. An efficient market assumes perfect (symmetric) information, where buyers and sellers know all the relevant facts.
2. Imperfect information means one or both sides lack the full picture, so they make choices they would otherwise avoid.
3. Information failure is therefore a source of market failure, because resources stop flowing to their most valued use.

Asymmetric information

1. Under asymmetric information one party in a transaction has more or better information than the other.
2. The better-informed party can act on that advantage, so decisions are distorted and resources are misallocated.
3. It gives rise to two distinct problems: adverse selection before a transaction and moral hazard after it.

Adverse selection

1. Adverse selection is a hidden-information problem that arises before a transaction, when the better-informed party self-selects to the other side's disadvantage.
   1. In the market for lemons, buyers who cannot tell a good car from a bad one offer only the average £6,000 for a car that might be worth £9,000 or £3,000.
   2. Owners of the £9,000 cars withdraw them because £6,000 undervalues them, so low-quality cars come to dominate.
2. In insurance, the highest-risk people are the keenest to buy cover because they know their own risk best.
   1. Their heavy claims push up premiums, which drives low-risk buyers out of the market.
   2. The market can shrink or even disappear as mainly bad risks remain, an outcome known as a missing market.

Moral hazard

1. Moral hazard is a hidden-action problem that arises after a transaction, when one party takes more risk because it does not bear the full consequences.
   1. An insured person may take less care, for instance driving faster or leaving a home unsecured, once any loss is covered.
   2. A bank that expects a government bailout may lend recklessly, knowing taxpayers would absorb losses, as in the £45.5bn UK rescue of RBS in 2008–09.
2. It often appears as the principal-agent problem, where an agent acts in their own interest rather than the principal's.
   1. A hired manager may chase personal perks instead of maximising returns for the shareholders who employ them.

Consequences and responses

1. Asymmetric information causes a misallocation of resources, because prices no longer reflect true costs and benefits.
2. It can leave missing or shrinking markets and lead to over-provision or under-provision of goods and services.
3. This creates a case for government intervention such as regulation and compulsory information provision.
   1. Governments can require disclosure, set minimum quality standards, or make some insurance compulsory to keep low-risk buyers in the pool.
4. Private responses include signalling, screening and warranties that reveal or guarantee quality.
   1. A warranty signals that a seller trusts their product, which reduces the lemons problem and helps good sellers trade.
5. How far these work depends on enforcement and cost, and there is a trade-off: compulsory insurance forces low-risk buyers to subsidise high-risk ones, trading efficiency for wider coverage.

How well can asymmetric information be solved?

1. There is a genuine toolkit for the problem: government disclosure rules, minimum standards and compulsory insurance, alongside private signalling, screening and warranties, can all narrow the information gap and revive trades that would otherwise collapse.
2. However, none of these removes the asymmetry completely. The informed side still knows more, enforcement is costly, and remedies bring side effects, since compulsory insurance forces low-risk buyers to subsidise high-risk ones, trading efficiency for wider coverage.
3. Effectiveness depends on how large and persistent the gap is, whether quality can be credibly verified, and the cost of the remedy relative to the misallocation it removes; heavy-handed rules risk government failure of their own.
4. On balance, asymmetric information can usually be reduced but rarely eliminated, so some misallocation remains whatever is done. The best mix of private and public responses depends on the market, the cost of obtaining information and how credible any signal or guarantee can be made.