Stanford economist @pawtrammell on why he refused to sign the "We Must Act Now" letter and calls banning automation a fool's errand: "I don't think work is good in and of itself. I think we've sort of brainwashed ourselves into feeling that way because it's necessary. But the ideal future to me is one in which we all have leisure." "It also doesn't seem very tractable to me. Let's say there is a machine that could really do everything we could do. With a trillion dollars you could build a…