Revealed preference

An economic and behavioural principle, formalised by Paul Samuelson, that what people actually choose is a more reliable signal of what they value than what they say they value. Talk is cheap; choices have costs, and so they expose underlying preferences in a way that stated opinions do not. The idea has migrated well beyond economics — it now turns up wherever someone wants to cut through professed beliefs to what the chooser is really optimising for, often unflatteringly. Bryan Caplan is a frequent champion of the move, as is Robin Hanson in his work on signaling.

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