The usual story is that we are careless calculators. The better story is that we are careful about the wrong things. It is tempting to call this irrational. It is more useful to ask what it is for. Consider the apology. It is a small thing, and small things are where habits live. A better account of luck would begin with the ordinary case rather than the laboratory one.
Why it persists
None of this is new. Adam Smith noticed most of it, and then the profession spent two centuries forgetting. The evidence here is thinner than the confident commentary suggests, and the honest position is a shrug with a direction of travel. Economists have spent decades modelling luck as a quantity. It behaves more like a weather system. We describe the departure from the model as an error. We might equally describe the model as a hopeful guess about us.
