Before revision:   We identify groupthink as the cause of this failure of information aggregation : As the number of agents grows, the actions of each individual depend more and more on the past actions of others, thus revealing less private information .
After revision:  With Normal signals, in the long-run, agents learn less from observing the actions of any number of other agents than they learn from seeing three other agents' signals. We identify groupthink as the cause of this failure of information aggregation : As the number of agents grows, the actions of each individual depend more and more on the past actions of others, thus revealing less private information .