Moral Hazard and Adverse Selection Explained with Examples | Economics

The education-as-signal model assumes education doesn't change ability but serves as a costly signal. In separating equilibrium, high-ability students acquire signals (education, warranties) while low-ability students cannot afford them. In pooling equilibrium, everyone obtains signals, making them useless for distinguishing types. For signaling to work, it must be credible and costly to fake, with costs differing between types. If signaling is too cheap, everyone obtains it (pooling). If too costly for low types but affordable for high types, high types acquire signals, allowing principals to distinguish types and offer appropriate contracts. In adverse selection, the agent has hidden knowledge about themselves while the principal lacks this information. Agents may want to reveal good information or hide bad information. Solutions include firms using advertising, warranties, and certifications; workers using education as ability signals; and governments making insurance mandatory to ensure both risky and safe types participate.

Signaling allows informed parties to reveal hidden characteristics through costly actions. In labor markets, education and certifications signal productivity—high-productivity workers face lower relative costs to obtain credentials. For signaling to work, better characteristics must correlate with lower signaling costs; otherwise, all agents send signals, eliminating distinguishing power. Warranties serve as product quality signals: high-quality producers can offer longer warranties because they expect fewer claims, while low-quality producers cannot afford such costs.

This section develops signaling theory as a solution to asymmetric information. Signaling conveys private information through costly signals that only high-quality agents can afford. Examples include warranties (defective products can't afford them), lineups (low-quality products can't attract demand), and certifications (bad sellers can't pass inspections). Advertising has three forms: informative (provides quality info), persuasive (influences preferences), and as a signal (firms waste money to signal quality, like Nike billboards). The debt-equity ratio signals financial health. Pre-trial settlement demands signal case strength. Michael Spence's 1974 education signaling model analyzes workers with ability (high ah or low al) where education has no effect on productivity but serves as a signal. The cost of education is lower for high-ability workers (ch) than low-ability workers (cl), making education a credible signal. Under perfect information, employers pay competitive wages equal to productivity. Under symmetric imperfect information, neither party knows ability, so wages cannot depend on ability. Workers have no incentive to get education since wages don't depend on it.

Three main solutions to adverse selection: (1) Signaling - quality parties prove their quality through credentials or warranties, (2) Screening - information-poor parties test and filter others through questionnaires or credit checks, (3) Regulation - government mandates like compulsory traffic insurance ensure participation from all risk levels.

Signaling allows informed parties to reveal private information through costly actions. Workers signal productivity through education and credentials. Screening allows uninformed parties to extract information through tests like probation periods. In the employer-worker example, employers use three-month probation periods to observe actual productivity. High-productivity workers easily meet requirements while low-productivity workers find it costly to mimic, enabling effective filtering.

Moral hazard occurs when one party takes excessive risks because another bears the consequences. In insurance, fully covering losses removes incentives for careful behavior. The solution involves designing contracts that align incentives—for example, deductibles or co-payments that make policyholders bear some cost of risky behavior. This principle applies broadly: venture capitalists must ensure entrepreneurs don't waste funds, employers must prevent employees from shirking, and lenders must ensure borrowers don't take excessive risks. Effective contract design requires understanding information asymmetries and incentive conflicts inherent in relationships. The analysis involves comparing expected utilities under different scenarios to find incentive-compatible contract terms.

Solving moral hazard requires designing contracts that make high effort incentive-compatible. A bonus contract pays fixed salary plus success-contingent bonuses. The incentive compatibility constraint requires: Salary - Effort_Cost + P_Success × Bonus > Salary + P_Success × Bonus (with low effort having no cost). This simplifies to Bonus > 250. The participation constraint ensures agents prefer working over outside options. With salary = 0 and bonus = 250, expected agent payoff = 200 > 100 outside option. The principal's expected profit comparison shows inducing high effort yields 280 vs 260 with low effort, making incentive contracts worthwhile.

Moral hazard can be prevented through deductibles (requiring insured parties to bear some losses), co-insurance (sharing losses), and performance-based incentives. These mechanisms align incentives between parties.

Multiple approaches address moral hazard: legal regulation limits lender recourse but has limitations; contractual restrictions specify spending but reduce flexibility; staged financing transforms one-shot interactions into repeated games with ongoing monitoring. Most powerfully, incentive design deliberately structures payoff divisions to align interests—for example, offering borrowers smaller shares of larger profits to incentivize repayment over shirking, demonstrating how contract design can overcome incentive misalignment.

Deposit insurance (guaranteeing savings up to €100,000 if a bank fails) creates moral hazard for banks. Knowing they will be bailed out, banks may engage in riskier activities than they would without this protection. 'Too big to fail' describes banks so large that their failure would cause catastrophic economic damage. When a bank becomes too interconnected with other financial institutions, its failure triggers a chain reaction causing other banks to fail. This creates moral hazard because banks know they will be bailed out, encouraging excessive risk-taking.

The 2008 crisis revealed that highly leveraged investment banks (Morgan Stanley, Bear Stearns, Lehman Brothers) had become so interconnected that their failure threatened the entire financial system. When Lehman Brothers collapsed, no large commercial bank remained to purchase it, demonstrating systemic risk had grown beyond manageable levels. Government bailouts created moral hazard—financial institutions knew taxpayers would rescue them if they took excessive risks. This tension between rescuing failing banks and discouraging future reckless behavior remains a central challenge in financial regulation.

Systemic risk refers to the danger that the failure of one large financial institution can trigger a cascade effect causing the entire financial system to collapse; institutions deemed 'too big to fail' receive government bailouts during crises, which creates moral hazard by potentially encouraging risky behavior since institutions know they will be rescued if they fail.

Large companies that are 'too big to fail' create moral hazard because they know the government will likely bail them out if they get into trouble. This implicit guarantee encourages these companies to take excessive risks: if risky projects succeed, they profit; if they fail, taxpayers bear the cost. This is similar to having insurance without paying for it, creating the same incentive problem as moral hazard. The rational response is to take many risky projects knowing that if things go wrong, taxpayers will pick up the tab.

The 'too big to fail' doctrine means certain institutions are so large and interconnected that their failure would destabilize the entire financial system. This creates moral hazard, encouraging excessive risk-taking because institutions expect government bailouts. The doctrine has expanded from banks to include technology companies, raising questions about who bears ultimate responsibility for systemic stability.

Contract theory studies how to design incentive-compatible agreements between parties. A contract specifies compensation structure, including conditions for penalties or rewards. Mechanism design is the science of organizing processes correctly to achieve desired outcomes. The lecture introduces this through the 2016 Nobel Prize winners (Hart and Holmström) who received the prize for contract theory. Poorly designed contracts can make outcomes worse for all parties, as demonstrated by examples including a university campus rule that blocked traffic for 15-20 minutes, a story about paying for rat extermination that led to people breeding rats, and the ЕГЭ exam that resulted in schools focusing on test preparation rather than genuine education.

Contract theory is a branch of mechanism design where agents possess private information and principals want to incentivize them to take good actions without agents revealing their private information. A classic example is airlines offering different ticket classes with varying amenities and prices, allowing self-selection without directly asking passengers about willingness to pay.

Contract theory represents the second major branch of mechanism design alongside auction theory, and it is equally important for economists. At its core, contract theory deals with situations where a principal wants agents to act in ways that benefit both parties, but agents possess private information that the principal cannot observe or verify. The classic airline example illustrates this: airlines cannot directly discriminate based on customer wealth or status, so they offer different 'contracts' (menu options)—economy class with basic service versus business class with premium amenities plus a small cup of wine. This allows airlines to capture more revenue while maintaining customer satisfaction across different segments. The key challenge is designing incentive-compatible contracts that align agent behavior with principal objectives despite asymmetric information.

Mechanism design principles apply even when there is no mechanism designer per se. When two parties negotiate a contract (like building a house), the contract itself becomes the mechanism. The theory applies because: (1) The contract must specify outcomes for different states (contingencies); (2) The contract must align incentives so parties have no reason to misrepresent information. Even with many stakeholders, if they can negotiate a set of goals, mechanism design principles can guide how to achieve them in a contract.

Mechanism design is an economic approach that starts with desired outcomes and works backward to design mechanisms (rules, institutions) that achieve them. Eric Maskin, a Nobel Prize winner (2007), established the theoretical foundations of this field. Unlike traditional game theory which analyzes existing situations, mechanism design asks 'what rules should we create to achieve this goal?' Maskin's key contribution was developing criteria to determine whether desired outcomes are achievable through some mechanism, without examining every possible mechanism individually.