A power pool is an entity that handles scheduling and dispatch functions for a group of power plants owned by multiple entities. Power pools are typically created by groups of utilities that desire the higher reliability and lower costs available from optimizing generation across a region. Pooling results in economic benefits to all participating utilities since higher-cost utilities have access to generation that may be lower-priced than their own, and lower-cost utilities receive additional power sales revenues. By using a pool, utilities do not need to continually rely on trying to trade power to obtain the savings but rather can obtain savings through the routine scheduling and dispatch process. Unlike ISOs or RTOs, power pools do not facilitate markets but rather do cost-based unit dispatch. Power pools were used extensively in the northeastern U.S. prior to deregulation, but the largest of the pools — PJM, New England, and New York — have now been replaced by ISOs.