As Saudi Arabia raised its production, the number of rigs drilling for oil in the US fell by 80 per cent. The only region in the world where drilling didn't drop was the Middle East. It wasn't long before there were calls, including from candidate Trump's energy adviser, for Opec to act to reduce supply and rescue prices that were too low for the American shale industry.
If the Nopec bill becomes law, there’s little incentive for anyone to hold spare production capacity. In recent decades this willingness has been an important safety valve to relieve the pressure of supply disruptions. A study by the King Abdullah Petroleum Studies and Research Center, initiated in 2016, assessed the annual economic benefit to the global economy of Opec's spare production capacity at between $170 billion and $200 billion through the reduction in price volatility in times of supply disruption. Without that buffer, oil prices could have spiked above $300 a barrel during the Libyan revolution, the study found.