what is the lemons theory 
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 because a seller does not know the value of a used car and therefore is unwilling to pay a premium on the chance that it might be a lemon premium car sellers are not willing to sell below the premium price so only lemons are sold 