I spent a night in the middle of the Bakken oil field – or more accurately, in the Walmart parking lot in Williston North Dakota – which really is in the middle of the oilfield. To remind you, Williston is/was the boom town that more than doubled in size in a few months when energy companies started exploiting the oil shale deposits. Oil was to be found everywhere. Prices went through the roof. Oil workers were sleeping anywhere they could find a bed. Investors built thousands of apartments.