Hypothetical bias - Catcher in the Rye edition

Economists tend to be skeptical of the answers people give on surveys - of people's stated preferences.  It's what we do that drives economic outcomes and well-being.  The trouble is that what we say on surveys often diverges from what we do when shopping.  The standard research finding is that, on average, people say on surveys that they are willing to pay about 2.5 times what they will actually pay when real money is on the line - a phenomenon referred to as hypothetical bias.  I've spent a lot of my career trying to devise survey techniques that get closer to the truth and I think we've made progress, but caution is warranted.

A lot of the research on hypothetical bias started in the 1980s and 90s when survey techniques started being more widely used to ask people to state their willingness-to-pay for environmental amenities.  Thus, you can might imagine my surprise when, recently re-reading Catcher in the Rye (published in 1951) the last chapter contained this clear, concise insight on hypothetical bias. 

A lot of people, especially this one psychoanalyst guy they have here, keeps asking me if I'm going to apply myself when I go back to school next September. It's such a stupid question, in my opinion. I mean how do you know what you're going to do till you do it? The answer is, you don't. I think I am, but how do I know? I swear it's a stupid question.