  This paper studies the organization of communication between biased senders
and a receiver. Senders can misreport their private information at a cost.
Efficiency is achieved by clearing information asymmetries without incurring
costs. Results show that only one communication protocol is efficient, robust
to collusion, and free from unnecessary complexities. This protocol has a
simple, adversarial, and public structure. It always induces efficient
equilibria, for which a closed-form characterization is provided. The findings
are relevant for the design of organizations that seek to improve
decision-making while limiting wasteful influence activities.
