The Economics of Information

Introduction

The economics of information explores how differences in information between buyers and sellers can lead to market inefficiencies. This chapter focuses on asymmetric information, adverse selection, moral hazard, and the role of government policy in addressing these issues.

Asymmetric Information

Asymmetric information occurs when one party in a transaction has more or better information than the other. This can lead to two main problems: hidden characteristics and hidden actions.

• Hidden Characteristics: One side observes something about the good being transacted that is relevant but not observed by the other party. Example: A seller knows whether a used car is a 'peach' (good) or a 'lemon' (bad), but the buyer does not.

• Hidden Actions: One side takes actions that are relevant for, but not observed by, the other party. Example: After buying insurance, a person may take more risks because the insurer cannot observe all their actions.

If information gaps are large enough, markets may fail to function efficiently or may shut down entirely, even when trade would be mutually beneficial.

Adverse Selection

Adverse selection arises when one party in a transaction knows more about a hidden characteristic and uses this information to decide whether to participate. This can lead to market outcomes where only lower-quality goods or higher-risk individuals participate.

• Example: In the used car market, if buyers cannot distinguish between peaches and lemons, they may only be willing to pay an average price. Sellers of high-quality cars (peaches) will not accept this price, so only lemons are sold.

• Example: In health insurance, high-risk individuals are more likely to buy insurance, raising costs for insurers and potentially driving low-risk individuals out of the market.

Signaling

Signaling is an action taken by an informed party to reveal private information to an uninformed party. Effective signals must be costly or difficult to fake for those without the desired characteristic.

• Example: Offering a warranty signals that a product is high quality, as only sellers confident in their product's reliability would offer such guarantees.

• Buyers can also signal, such as by providing proof of good health when applying for insurance.

Hidden Actions: Markets with Moral Hazard

Moral hazard occurs when one party takes actions that are not fully observable by the other and that affect the outcome of the transaction. This often arises in insurance and employment relationships.

• Example: Drivers with airbags may drive more recklessly, knowing they are protected, increasing the likelihood of accidents.

• Example: Employees may not work as hard if their effort is not directly observable by employers.

Principal-Agent Problem

The principal-agent relationship describes situations where one party (the principal) hires another (the agent) to perform a task. The principal must design incentives to align the agent's actions with their own interests.

• Example: Employers use contracts, bonuses, or efficiency wages (wages above the minimum necessary) to motivate employees.

Reducing Moral Hazard

• Deductibles, co-payments, and coinsurance: These require insured individuals to bear part of the cost, reducing the incentive to take excessive risks.

• Efficiency wages: Paying above-market wages can increase worker motivation and reduce shirking.

Government Policy in a World of Asymmetric Information

Governments can intervene to address market failures caused by asymmetric information and moral hazard.

• Taxing risky behavior (e.g., taxes on cigarettes or alcohol) to discourage actions that increase costs for others.

• Subsidizing healthy behavior (e.g., subsidies for gym memberships or preventive care).

• Mandating deductibles or co-payments in insurance markets to reduce moral hazard.

Unemployment benefits can create moral hazard by reducing the incentive to search for work. Policymakers must balance providing support with maintaining incentives for job search.

Law enforcement faces a similar principal-agent problem: a small probability of detection combined with severe punishment can deter crime, even if not all crimes are detected.

Evidence-Based Economics: Applications and Problems

• Why do new cars lose value immediately? Buyers suspect hidden defects (lemons), so used cars sell for less, even if they are high quality.

• Why is private health insurance expensive? Adverse selection leads to a pool of higher-risk individuals, raising costs for insurers and premiums for everyone.

• Does competition improve insurance markets? Not always—if insurers cannot distinguish between high- and low-risk customers, competition may not lead to efficient outcomes.

Worked Example: Health Insurance and Adverse Selection

Suppose there are 50 healthy and 50 unhealthy people. Healthy people expect $200 in medical costs per year; unhealthy people expect $600. The insurance company cannot distinguish between them and offers a plan charging $450 for full coverage.

• Who buys the plan? Unhealthy people benefit (pay $450, get $600 in coverage), so they buy. Healthy people pay more than their expected costs, so they may not buy.

• Expected payout and profit: If only unhealthy people buy, the insurer pays $600 per person but collects only $450, leading to losses.

• Alternative plan: The insurer offers a second plan: $50 premium plus 30% coinsurance. Healthy people may prefer this plan, while unhealthy people may still prefer full coverage. This can help segment the market and reduce adverse selection.

Summary Table: Key Concepts in the Economics of Information

Key Equations

• Expected Cost for Insurance Company:

• Profit for Insurance Company:

Additional info: The above notes expand on the brief points in the slides, providing definitions, examples, and context for each concept. The summary table and equations are inferred to support student understanding and exam preparation.