There is often a vast gulf between how people say they behave and how they actually behave. (In economist-speak, these two behaviors are known as declared preferences and revealed preferences.) Furthermore, when it costs almost nothing to fib—as in the case of a government survey like this one—a reasonable amount of fibbing is to be expected. The fibs might even be subconscious, with the subject simply saying what she expects the surveyor wants to hear.
