The textbook treats patience as a preference to be revealed. In practice it is a story we tell ourselves after the fact. A pattern this consistent is not a character flaw. It is a design feature, and design features can be worked with. The lesson is modest. Build for the person who exists, not the one in the model. The point is not that people are foolish. The point is that patience is expensive, and we economise on it like everything else.
The cost of being right
There is a version of this essay that ends with a policy prescription. This is not that version; the mechanism is interesting enough on its own. It is tempting to call this irrational. It is more useful to ask what it is for. Economists have spent decades modelling patience as a quantity. It behaves more like a weather system. Consider the empty diary. It is a small thing, and small things are where habits live.
