"The FPC acquired authority to regulate the prices at which producers sold natural gas to interstate gas pipelines for resale. Previously, the FPC regulated the prices at which interstate pipelines sold gas but not the price at which they purchased that gas from producers. This augmentation of the FPC's price-setting powers is shown to be, in this work and many others, the single most important cause of the natural gas shortages that first appeared in the late 1960s."