Institutions know all this, of course, which is why the tip jar is so rarely left to chance. The point is not that people are foolish. The point is that hope is expensive, and we economise on it like everything else. Notice how rarely anyone is argued out of the tip jar, and how often they are simply moved past it by a change in circumstance. A pattern this consistent is not a character flaw. It is a design feature, and design features can be worked with.
Why it persists
We describe the departure from the model as an error. We might equally describe the model as a hopeful guess about us. In the studies we have, the effect is modest, reliable and almost entirely ignored by the people it describes. Put a number on hope and it becomes a target; put a target on it and the number stops meaning what it meant. A pattern this consistent is not a character flaw. It is a design feature, and design features can be worked with.
