Ask most people why they did what they did and they will give you a reason; ask them again a week later and the reason will have quietly changed. None of this is new. Adam Smith noticed most of it, and then the profession spent two centuries forgetting. Consider the borrowed book. It is a small thing, and small things are where habits live. What looks like fairness from the outside is usually something simpler from the inside: tiredness, a deadline, a wish not to look foolish.
What follows
The evidence here is thinner than the confident commentary suggests, and the honest position is a shrug with a direction of travel. Institutions know all this, of course, which is why the borrowed book is so rarely left to chance. 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 measure that matters is not what people say about fairness but what they do when nobody is scoring.
