Investor-owned utility (IOU) vs. municipal utility vs. rural electric cooperative

U.S. electric utilities generally fall into three ownership categories. An investor-owned utility (IOU) is a privately owned, publicly traded, for-profit company, rate-regulated by state or federal authorities and authorized to earn a set rate of return. A municipal utility (a type of publicly owned utility) is operated by a city or other local government, generally on a not-for-profit basis. A rural electric cooperative is owned by and operated for the benefit of the customers it serves, typically in areas other utilities didn't find profitable to serve, and most were originally financed by the federal Rural Electrification Administration (now the Rural Utilities Service).