In the studies we have, the effect is modest, reliable and almost entirely ignored by the people it describes. Understanding people turns out to be a more urgent task than changing them, and a great deal harder. We describe the departure from the model as an error. We might equally describe the model as a hopeful guess about us. The measure that matters is not what people say about risk but what they do when nobody is scoring.
The ordinary case
The point is not that people are foolish. The point is that risk is expensive, and we economise on it like everything else. Institutions know all this, of course, which is why the deadline is so rarely left to chance. The textbook treats risk as a preference to be revealed. In practice it is a story we tell ourselves after the fact. Consider the deadline. It is a small thing, and small things are where habits live.
