Economists are something like social scientists with physics envy. They still don't manage to get good at prediction and have a corpus of well replicated phenomena.
Economists do have a large corpus of well replicated phenomena, and they do have good predictive ability. The problem is that people want economists to make predictions on subjects that are least understood, or even ones that economic theory suggests cannot be generally predicted, such as stock market movements. Sure, economists can't do that, but they (mostly) don't claim to be able to do that.
Another month, another rationality quotes thread. The rules are: