Keynes’ General Theory provides an interesting metaphor for asset markets: they are like newspaper competitions where contestants have to pick up the six prettiest faces from a hundred photographs, and the prize would go to one whose choice is closest to the average preferences. Keynes did not...

A decision maker is contemplating an action whose outcome is state dependent. She has a ‘prior’ over the states of the world and before choosing an action, she can consult an ‘expert’. We model the communication game between the decision maker and the expert as a ‘cheap-talk’ game....