Title: Sticking with what (barely) worked
Description: "Outcome bias occurs when an evaluator considers ex-post outcomes when judging whether a choice was correct, ex-ante.  We formalize this cognitive bias in a simple model of distorted Bayesian updating.  We then examine strategy changes made by professional football coaches.  We find they are more likely to revise their strategy after a loss than a win - even for narrow losses, which are uninformative about future success.  This increased revision following a loss occurs even when a loss was expected, and the offensive strategy is revised even when failure is attributable to the defense.  These results are consistent with our model's predictions"--National Bureau of Economic Research web site.