The Libor controversy is in full swing: story here.
Banks are "polled" to determine what rates they would lend to each other to arrive at Libor. They lie.
This is a problem with surveys. People say a lot of things which they dont do, or dont mean. Actions speak louder than words. The only way to determine a loan rate is to actually ask for a loan-or look at a previous trade price of the loan interest rate. Otherwise, it has no meaning.
This is a general problem in all surveys-psychology, sociology, etc. are full of these. Most give no information; Humans don't know themselves that well; inspite of their well developed vocabularies and "rational" talk. We are all animals-and mostly clueless about what we do and why we do it.
A good narrative of why I did something is always there---but prove to me that it is the reason? e.g. I want to eat melons today---so I go and buy a melon and eat it. The animal model simply says---the body needed melon, triggered the conscious mind to make a statement that I want a melon, and made the body go out and get melon. The desire is unconscious-but the actor thinks she is actually making a conscious decision to eat a melon.
This is also called attitude-behavior discrepancy in psych circles; we are full of it.