Swing states

Is American tight oil really now the world’s swing supplier?

You can almost guess how the crude market moved in the last couple of months by looking at Baker Hughes's weekly rig data. More rigs in play? Oil firmed. Fewer? Crude dropped. American tight oil's remarkable rise in recent years transformed the global supply picture. But, along with Opec's reluctance to cut production to prop up prices in the past two years, tight oil also changed ideas about energy security. Before tight oil boomed, balancing the market was the job of Saudi Arabia. In an emergency-a sudden supply shock-or during a damaging price spike, the unwritten agreement between the International Energy Agency (IEA), whose members maintain an emergency inventory to cope with an interru