The Market for Lemons cars, the dearth of formal credit markets in developing countries, and the difficulties that the elderly encounter in buying health insurance. However, not all players in a given market will follow the same rules or have the same aptitude of assessing quality. So there will always be a distinct advantage for some vendors to offer low-quality goods to the less-informed segment of a market that, on the whole, appears to be of reasonable quality and have reasonable guarantees of certainty. This is part of the basis for the idiom buyer beware. This is likely the basis for the idiom that
Beware of the Dog (short story) send in a fake RAF commander to convince him to divulge his squadron’s location, he stares him straight in the eye and says nothing more than “My name is Peter Williamson. My rank is Squadron Leader and my number is nine seven two four five seven.” Beware of the Dog (short story) "Beware of the Dog" is a 1944 World War II story by Roald Dahl which was originally published in "Harper's Magazine" and later appeared in his "" collection. Its basic plot was adapted into the 1965 movie "36 Hours", starring James Garner and Rod Taylor, and the TV