John Constable &Matt Ridley,CapX
Imagine a sausage factory the luckiest, most profitable sausage factory in the world. Its machines crank out their sausages, and lorries carry them to supermarkets. So far,so normal.
But this particular factory makes as many sausages as the management and staff choose. If they feel like taking the day off, the lorries and shelves stay empty. If they want to go a bit wild, and they sometimes construct so many sausages that there aren't enough lorries to select them absent. Or they carry on cranking out sausages even if the shelves are already full.
Source: realclearenergy.org