Efficient Markets and Perfect Information

Robert Skidelsky on the efficient markets hypothesis and  New Classical economics generally:

Every general crisis involves self deception as well as the deception of others. In Donald Rumsfeld’s immortal phrase, it is the “unknown unknowns” which trip us up. If only one person were perfectly informed, there could never be a general crisis.

But the only perfectly informed person is God, and He does not play the stock market.

[Skidelsky, Robert, “Keynes: The Return of the Master”, Audible Inc, 2009]