Network utilities have a significant share in the national product and disproportionately influence its growth. These ""infrastructure"" industries - including electricity, telcommunications, transportation, gas and water - provide services that are critical to economic development and to improving the lives of poor people. This book focuses on infrastructure regulation that both promotes efficient markets and corrects for market failures. Each sector demands unique regulatory solutions that balance the goals of growth and efficiency with those of social equity and service access for the poorest. It explores the history of public utilities, the trend towards privatization and liberalization, and the ways in which fundamental principles of regulation can help navigate the promises and perils of service delivery.