TANSTAAFL: A rather cumbersome and usually hard to remember acronym for the expression "There ain't no such thing as a free lunch. This is a favorite saving of many economists because it highlights, albeit in a grammatically questionable manner, the fundamental problem of scarcity. The phrase serves to emphasize that seemingly "free" lunches are not really free. While they might be free to the customer, someone must pay, that is, incur an opportunity cost of foregone production. The lunch eaten by one person cannot be eaten by another.
