> That some/most economists like to use. There is a huge field in economics (and econophysics and stuff) that focused on actual irrational behaviour (like trend

> That some/most economists like to use. There is a huge field in economics (and econophysics and stuff) that focused on actual irrational behaviour (like trend-following, trying to time the market, predicting the 'mood' of the market) Behavioral economics is really interesting, yes, but this isn't even an example of irrational behavior (in the technical meaning of "rational"). What a consumer says they want isn't necessarily the same as what they do want, as determined by their revealed preferences (ie, what they do with their actions). If those are self-consistent, the behavior is rational, even if it contradicts what they say they want.