We introduce a new model of aggregate information cascades where only one of two possible actions is observable to others. When called upon, agents (who decide in some random order that they do not know) are only informed about the total number of others who have chosen the observable action...

We test the no-trade theorem in a laboratory nancial market where subjects can trade an asset whose value is unknown. Subjects receive clues on the asset value and then set a bid and an ask at which they are willing to buy or to sell from the other participants. In treatments with no gains from...