We study information flows in an organization with a top management (principal) and multiple subunits (agents) with private information that determines the overall efficiency of the organization. Under centralized communication, eliciting the agents' private information may induce the principal to manipulate aggregate information, which obstructs an effective use of information for the organization. Under hierarchical communication, the principal concedes more information rent due to loss of control, but is able to use the agents' information more effectively. The trade-off between the organizational structures depends on the likelihood that the agents are efficient. Centralized communication is optimal when such likelihood is low. Hierarchical communication, by contrast, is optimal when it is high.