Isn't economics one of those disciplines where the more seriously a prediction is taken the less likely it is to be accurate. If people believe a prediction they alter their behavior and as a result the prediction fails.
So it isn't a particular problem of economics. The problem of economics is testing theories. I would guess that most economists have a theory that never gets tested, because you can't test them in a lab, only in real life, the depth of knowledge just isnt there to know what will work, what won't, and popular but wrong theories aren't proven wrong fast enough. I cant reasonably say whether bald tyres will cause a crash, because no ones seen bald tyres before.