Every one of us runs the same shortcut, and every one of us believes we are the exception. Nobody sets out to be governed by the sunk cost, yet it shapes an astonishing share of the ordinary day. The measure that matters is not what people say about restraint but what they do when nobody is scoring. 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.
Three kinds of mistake
Every one of us runs the same shortcut, and every one of us believes we are the exception. The textbook treats restraint as a preference to be revealed. In practice it is a story we tell ourselves after the fact. 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 lesson is modest. Build for the person who exists, not the one in the model.
