Advice from Multiple Experts: A Comparison of Simultaneous, Sequential, and Hierarchical Communication

In this paper, I analyze an example in which two perfectly informed experts advise a decision maker. Each expert has private information about her own bias. I show that consulting two experts is better than consulting just one. I compare the efficiency of information transmission between simultaneous, sequential, and hierarchical forms of communication. I show that simultaneous communication achieves the highest efficiency, followed by sequential and hierarchical communication. However, hierarchical communication, in which a second expert chooses whether to block the first expert's message, achieves a moderate level of efficiency, even though the decision maker receives only one message. Finally, there are preference settings in which both sequential and hierarchical communication are superior to simultaneous communication.