Adverse selection

July 27, 2023
Adverse selection occurs when the buyer or the seller knows the other party does not see an item's quality. People with risky occupations or lifestyles are more likely to get life or disability insurance, as they can make a claim more efficiently. The purchaser may be at an offset in the deal if the seller has more knowledge about the goods or services on sale than the purchaser has. The used-car and insurance markets both exhibit adverse selection.

What is adverse selection?

The term "adverse selection" describes situations in which one party (either the seller or the buyer) has complete knowledge about the quality of a product that the other party does not. It is an example of the use of asymmetric information. When one side of a deal has more material knowledge than the additional, asymmetric information or information failure arises. In most transactions, the seller has the upper hand regarding expertise. With symmetric information, each party has the same amount of data.

Adverse selection refers to people with risky occupations or regularly engaging in risky behaviors who are more likely to buy insurance policies. The purchaser in this scenario has superior expertise (concerning the purchaser's health). Insurance firms counteract adverse selection by restricting coverage or increasing rates in response to the risk of significant claims.

The concept of the adverse selection

Adverse selection happens when one party to a trade, agreement, or negotiation withholds essential information that might provide the other party an unfair advantage. When people do not have the same level of access to information, the market cannot function properly.

1.     Asymmetry of information

It is information asymmetry when one party knows that the other does not. When purchasing an automobile from a dealership, for example, it presents information asymmetry. It happens because the salesman understands the drawbacks of buying that vehicle. For instance, it is expensive to repair, wastes a lot of gas, and does not have additional features worth having.

However, the customers are in the dark about these deficiencies except for what the salesman has said. Without actually using the vehicle, there can be so much they can learn about it via inspection. Buyers are unlikely to learn about the vehicle's flaws before purchasing. In this case, the vendor had access to additional details than the buyer. The customer cannot make a sound decision because of the lack of information.

2.     Exploiting information asymmetry

If they are being honest, the salesman will notify the customers about the vehicle's drawbacks. Adverse selection occurs when a seller covers up a product's flaws to make a profit. The salesperson can close the deal by playing on the buyer's lack of knowledge of the automobile's drawbacks.

It is essential to differentiate between the ideas of adverse selection and moral hazard. Moral hazard results from parties engaging in a transaction with incomplete or false information due to adverse selection.

Repercussions of adverse selection

A purchaser might be at a loss in a trade if the seller has more knowledge about the goods or services on sale than the buyer has. When the management of a firm believes the price of their stock is higher than it is, they may be more inclined to issue shares to the public; unfortunately, this may cause investors to make a wrong investment decision. When selling a used automobile, the seller could try to make up for the vehicle's flaw by asking for a higher price from the buyer.

Since customers do not have information access held by sellers or manufacturers, the adverse selection often results in higher prices. As a result, consumers may be less inclined to spend money on goods and services. Or it might leave out customers who cannot pay or have access to resources that would help them make more informed purchases.

Consumers' health and welfare could be impacted negatively due to adverse selection effects. Consuming a defective product or drug you bought without proper knowledge might have serious health consequences. Customers may mistakenly perceive a safe intervention as too dangerous, leading them to avoid purchasing certain healthcare items (such as immunizations).

Adverse selection within the insurance sector

Insurers have higher premium take-up rates from high-risk customers due to adverse selection. Companies lose money when paying additional incentives or claims for average-risk customers while charging them the average fee. Nevertheless, the firm has other resources to pay these benefits because of increased premiums for high-risk customers.

 An adverse selection that may occur in the automobile insurance industry is when a customer acquires coverage by lying about where they live and claiming they are located in a low-crime region when they dwell in a high-crime area. The applicant runs a far higher chance of having their car stolen, broken into, or otherwise destroyed if they keep it in a high-crime place instead of a low-crime region. Small-scale adverse selection could happen if an applicant lies about where they keep their car overnight and says it is in a garage when parked on a public street.

Another example of adverse selection; Consider two people interested in purchasing life insurance policies from a given organization. While the first individual has hypertension and does not exercise, the second has no medical conditions and works out regularly.

Not exercising regularly increases the chance of developing hypertension, which reduces life expectancy compared to a healthy individual. The insurance business will be at a disadvantage if it cannot determine whether or not the two prospective policyholders are in good health.

The insurance firm requires new customers to fill out registration documents as part of the onboarding procedure. Prospective customers must disclose any preexisting medical issues to work with the firm. The hypertensive may hide his illness to get the same care as the customer who did not have hypertension and did not have to pay higher premiums.

Adverse selection occurs when critical information is withheld. Since the insurance business will engage in a contract with a hypertensive patient without knowing the policyholder's health state, the insurance firm will be at a disparity.

Mandatory acquisition of the health insurance cover

Private insurance plans are an essential component of the American healthcare system. As a result, young, healthy individuals are less likely to sign up for health insurance, contributing to the challenges of adverse selection. The result was increased rates, making coverage out of reach for many.

The need for health insurance coverage was included in the Act of patient protection and affordable care. Non-insured individuals are subject to a tax penalty. The assumption is that if more people get insurance, the average cost per person will go down since lower-risk individuals will have contributed to the "insurance pool."

Buyer-seller adverse selection

When a customer plans to buy something from a vendor but has more knowledge about the item, the vendor may experience adverse selection. Since the buyer is entering into an arrangement with a vendor who may not voluntarily provide full facts about the goods offered, the buyer is disadvantaged.

For instance, if a buyer is interested in purchasing a used automobile, but the seller cannot disclose any flaws in the vehicle, the purchaser will be at a disadvantage. When a consumer gets a car without the vendor identifying any weaknesses in the vehicle, this is known as "adverse selection."

Capital markets with adverse selection

Some assets are more vulnerable to adverse selection in the capital markets than others. For instance, a rapidly expanding corporation could sell public shares at a premium. The investor is susceptible to adverse selection if it is assumed that capital market managers have access to confidential information about the firm that is unavailable to the general public.

Executives may, for instance, be acquainted with a concealed valuation of the firm that shows the offer price is higher than the private evaluation. If investors buy the shares without realizing the firm is overpriced, they will be at a loss. Adverse selection would cease to exist if, after management informed investors of the company's overvaluation, those investors continued to acquire shares.

Market makers' and specific institutional traders' stocks also differ. The identities of the company's largest stockholders are disclosed to the public once per quarter. The investing public may not be aware that some market participants have an "axe to grind," such as an overwhelming urge to acquire or sell.

Solving the impacts of adverse selection

Adverse selection of insurance plans and similar market situations can destroy industries, which is a significant concern. It is not an intractable problem, however. Below is an explanation of how to address this problem.

1.     It might be settled monetarily, with the less-informed party being reimbursed for taking on greater risk than the more-informed party. Insurance rates might be raised if a corporation believes a policyholder would exploit information gaps in their favor. The organization will not be shortchanged even if applicants are dishonest about their circumstances.

2.     However, negotiating parties may adjust terms to lessen the impact of knowledge asymmetry's benefits and drawbacks. The potential buyer of the automobile in the previous example would recommend taking it for a few test drives before committing to a purchase to avoid being scammed.

3.     The most practical action would be for the marginalized to gather all relevant data. That is why insurance firms employ people called underwriters to check out applicants and make sure their stories add up.

Moral hazard vs. adverse selection

Moral hazard and the related field of adverse selection economics examine the effects of deceiving or withholding information from contracting parties. Nonetheless, these ideas are not identical, and their ramifications are different. One may be able to comprehend the distinctions by comparing the two phrases below;

·       Moral hazard

1.     A moral hazard occurs when one party to a contract or agreement provides incorrect or deceptive data to the other, causing the other side to breach the terms of the contract after it has already started.

2.     These instances take place after the contract or deal has been finalized.

3.     Here, the party spreading false information does so with full awareness of the potential repercussions for themselves and the opposing party.

·       Adverse selection

1.     The term refers to a situation in which one party to an agreement or transaction conceals crucial information from the other to acquire an unfair advantage.

2.     These situations happen just before a sale is finalized.

3.     One side takes advantage of the other's naiveté or lack of information.

The Lemon crisis

The lemons dilemma occurs when there is a discrepancy in the knowledge held by the purchaser and the seller about the true worth of an investment or commodity.

George A. Akerlof, a professor of economics at the University of California, Berkeley, first proposed the lemons dilemma in a paper titled 'The Market for Lemons' published in the late 1960s. The situation was described using a catchphrase inspired by the phenomenon of secondhand vehicles. Used faulty autos are occasionally referred to as "lemons," which Akerlof used to demonstrate asymmetric information. The lesson is that the only remaining used autos on the market will be lemons owing to adverse selection.

The lemons issue arises when there is a discrepancy between the value that purchasers and sellers assign to an investment, as is the case in the consumer goods market, the business goods market, and the investment market. The insurance and the credit systems are only two examples of financial sectors affected by the lemons issue. For instance, a lender in the field of corporate finance possesses imperfect and asymmetrical information on the debtor's true credibility.


Conventional economic and financial models incorrectly assume that all participants in a market have equal access to and knowledge of the same data set. One area in which this is especially true is in the knowledge gap between vendors and customers. Adverse selection occurs when market inefficiencies arise due to information asymmetry. Applicants in insurance marketplaces often conceal essential information about their riskiness because they know more about themselves than insurance firms.