Every significant index attests to the extraordinary growth of the electric-power industry throughout the first four and a half decades of the present century. Physical output multiplied forty times between 1900 and 1939, a record exceeded during this period only by the automobile and cigarette industries. Labor efficiency and efficiency in the use of fuel increased well above the average for industry generally, and yet employment rose ninefold. Fixed assets were approximately ten times greater at the end of the period than they were at the beginning. Electric rates—the cost of the product to the consumer—have declined throughout. Here is a record of very great progress, even for an industry that was in its infancy in 1900—increased investment, efficiency, employment, and output, and reduced prices. It raises some interesting questions for public policy, questions related both to the future of the electric-power industry and to possibilities in other fields where lessons drawn from this experience may be pertinent.