In the studies we have, the effect is modest, reliable and almost entirely ignored by the people it describes. The textbook treats doubt as a preference to be revealed. In practice it is a story we tell ourselves after the fact. Nobody sets out to be governed by the polite refusal, yet it shapes an astonishing share of the ordinary day. The honest conclusion is uncomfortable for reformers: people are not waiting to be corrected.
A better question
None of this is new. Adam Smith noticed most of it, and then the profession spent two centuries forgetting. Notice how rarely anyone is argued out of the polite refusal, and how often they are simply moved past it by a change in circumstance. Every one of us runs the same shortcut, and every one of us believes we are the exception. What looks like doubt from the outside is usually something simpler from the inside: tiredness, a deadline, a wish not to look foolish.
