The Market for Lemons

George Akerlof's famous explanation of how hidden quality can drive good products out of a market, using used cars as the example.

In 1970 George Akerlof published a short paper called “The Market for ‘Lemons’”. In American slang, a lemon is a car with hidden defects. Akerlof’s paper, initially rejected by several journals as too trivial, became one of the most influential in economics.

The story

Imagine a used car market where half the cars are good and half are lemons. Sellers know which kind they own. Buyers cannot tell them apart.

Suppose a good car is worth 10,000 dollars to buyers and a lemon is worth 4,000 dollars. A buyer who cannot tell the difference might offer the average: 7,000 dollars. But owners of good cars will not sell for 7,000 when their cars are worth more. So good cars leave the market. Buyers then realise that the cars on sale are mostly lemons, and lower their offers further. In the extreme, only lemons are sold. This process is called market unravelling.

Adverse selection

The general problem is called adverse selection: when one side knows more about quality, the mix of things actually traded shifts toward lower quality. Akerlof showed that this can shrink or even destroy markets that would benefit both buyers and sellers.

The same logic appears in many places:

Insurance: people who know they are high-risk are keener to buy insurance, raising costs for insurers.
Lending: borrowers who know they are risky may be most eager to borrow.
Hiring: if employers cannot judge workers’ ability, good workers may be underpaid.

Why a nearly new car loses value fast

A car driven off the dealer's lot can lose a large part of its value almost immediately, even though it is nearly identical to a new one. One reason is the lemons problem: buyers wonder why someone would sell a car so soon, and suspect a hidden problem. The price reflects that suspicion.

How markets respond

Markets have developed many ways to fight adverse selection: warranties, inspections, dealer reputations, vehicle history reports and certification programmes. Governments also step in, for example with lemon laws in many U.S. states that let buyers return seriously defective new cars.

Thinking the lemons problem means sellers are dishonest

The problem does not require anyone to lie. It arises simply because sellers know more than buyers. Even honest sellers of good cars are hurt, because buyers cannot tell them apart from sellers of lemons.

Key takeaways

Akerlof's 1970 paper showed how hidden quality can drive good products out of a market.
Adverse selection shifts trade toward lower quality when sellers know more than buyers.
The same problem appears in insurance, lending and hiring.
Warranties, inspections, reputations and laws help reduce it.