That's another significant element of the equation. If oil is $100 a barrel, then it's worthwhile spending $80 to extract the difficult stuff. But it's not a fundamentally very productive endeavour. In fact, it's a matter of pouring more and more resources (skills, machinery, energy etc) into a vanishing resource. Not a very smart strategy.

This is what they mean when they say that the market will provide if the price is right. Though I think that they are materially wrong on that. Canada has the world's second biggest hydrocarbon reserves. But they just can't seem to ramp up production the way the economists predicted. It's just too hard.

_{It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II}