Consider a group of experts who are certain that fact X is true. This fact could be something such as global warming is occurring and is caused by human activity. They sign a statement saying X is true. If the experts turn out to be wrong, however, they will probably pay at most only a small reputational cost. This low error cost reduces the authority value of the expert’s statement. I propose a reputation commitment mechanism that would increase the personal cost to the experts of being wrong and so increase the authority value of their statement.