A few years ago a well-known economist named David Romer published a paper in a top economics journal* arguing that professional football teams don't "go for it" nearly often enough on fourth down. The question, of course, is how this can persist in equilibrium. If Romer is correct, wouldn't teams have a strong incentive to change their strategies? Of course it's possible that he is correct, but that no one ever knew it before the paper was published. But then would the fact that the recommendation has not been widely adopted** constitute strong evidence that he is not correct? The paper points out two possible reasons why not. First, the objective function of the decision-makers may not be to maximize the probability of winning the game. Second and more relevant for our purposes, there may be some biases at work. The key point is this quote from the article (page 362):

"Many skills are more important to running a football team than a command of mathematical and statistical tools. And it would hardly be obvious to someone without knowledge of those tools that they could have any significant value in football."