The authors argue that, although decentralization has advantages in finding low-cost solutions, these advantages are accompanied by coordination problems, which lead to delay or duplication of effort or both. Consequently, decentralization is desirable when there is little urgency or a great deal of private information, but it is strictly undesirable in urgent problems when private information is less important. The authors also examine the effect of large numbers and find that coordination problems disappear in the limit if distributions are common knowledge.