Economics has a hard time predicting economic markets due to the Lucas critique -- if people know the predicted environment, they will change their behaviour (r

Economics has a hard time predicting economic markets due to the Lucas critique -- if people know the predicted environment, they will change their behaviour (redirect investments/savings/etc) based on it and the prediction becomes inaccurate. Economics has a nearly impossible time predicting stock prices - the Lucas critique applies hundredfold here, if market participants learn of more accurate economic predictions, they would immediately incorporate in their models and stock prices would have already adapted. (Not to speak of the randomness that a market with a billion participants exhibit, much of which is not really random but unexplainable by a a broad-strokes economic model...)