Market for Lemons

The Market for Lemons is George Akerlof's 1970 model of how adverse selection can drive a market to complete collapse. In a market where sellers know the quality of their goods and buyers do not, the price converges to the average quality of the goods actually offered — which is below the value of any high-quality item. High-quality sellers withdraw, the average falls further, and the market unravels until only "lemons" remain. The model is not merely about used cars; it is a general demonstration that information asymmetry at the entry point can destroy surplus that would exist under full information.

The paper's deeper contribution was methodological: it showed that information asymmetry could be modeled rigorously within standard equilibrium frameworks, opening the door to signaling theory, screening models, and the modern economics of contracts. Akerlof's lemons are the canonical example of how hidden types distort market composition — and how the distortion, left unaddressed, becomes a coordination failure that no bilateral bargain can repair.