The basic tenet of the lemons principle is that low-value cars force high-value cars out of the market because of the asymmetrical information available to the buyer and seller of a used car. This is primarily due to the fact that a seller does not know what the true value of a used car is and, therefore, is not willing to pay a premium on the chance that the car might be a lemon. Premium-car sellers are not willing to sell below the premium price so this results in only lemons being sold.