…in hindsight, every price is wrong.
That’s Eugene Fama, from Fama vs. Thaler. I enjoyed this part too:
Twenty years ago my criticism of behavioral finance was that it is really just a branch of efficient markets, because all they do is complain about the efficient-markets model. I’m probably the most important behavioral-finance person, because without me and the efficient-markets model, there is no behavioral finance. I still think there is no full-blown testable behavioral asset-pricing model.
I have more sympathies for behavioral finance than that, still the dialogue is worth reading in its entirety. Judged as a debate, Thaler loses.
Hat tip goes to Allison Schrager.