Thomas de Zengotita recommends this book: Expert Political Judgment : How Good is It? How Can We Know? Zengotita writes
The answer is shocking at first but makes perfect sense on further reflection. It seems that experts (not only in politics but other areas as well) are worse judges of what is likely to happen than a reasonably well-informed ordinary citizen.
How could this be? Well, the real fun is in the details of the research, but the common-sense foundation for the result is simply stated. First, experts are likely to have some framework of interpretation to defend, so they force facts into that framework. Second, experts have a gazillion factors to consider when they make predictions, so they get lost in a gazillion plus scenarios and lose track of the obvious.
As a result of these all-too-human inclinations, experts actually come out worse as predictors than what you would get if you just chose outcomes at random.
Makes sense to me…