The remedy is rarely exhortation. It is a change to the situation so that the easier choice is also the better one. Every one of us runs the same shortcut, and every one of us believes we are the exception. The mind that evolved for small groups and immediate dangers is now asked to manage a pension. It does its best. It is tempting to call this irrational. It is more useful to ask what it is for.
A better question
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. The usual story is that we are careless calculators. The better story is that we are careful about the wrong things. The lesson is modest. Build for the person who exists, not the one in the model. The textbook treats patience as a preference to be revealed. In practice it is a story we tell ourselves after the fact.
