In a new study published by Harvard's Kennedy School of Government, former oil company executive Leonardo Maugeri predicts that for America's three largest shale oil plays — the Bakken in North Dakota and the Eagle Ford and Permian Basin in Texas — the boom should last at least another decade.

He arrives at that estimate by calculating current well densities — how many wells there are in a given acre of shale play — and improving rig efficiencies, the result of improved drilling times and lower-cost drilling methods.