I still see this as treating the symptoms, and see the root cause as: too many people. If the world population were 1.5 billion instead of 6 billion, there would be no energy problem.
I agree that in the short term (and probably also in the long term) there's nothing we can do about this root cause, and agree that price increases are one way of treating the symptom.
OK, you are digging deeper down in the root structure.
So, I'll frame my response a bit. If we wish to conserve gasoline in the USA w/o population restrictions..... raising the price is the way to go.
While I don't disagree with your premise, the actual numbers you use might not hold up. I'd have to check the actual numbers, but if all of the 1.5B people used energy at the rate that the average US citizen does, we might be using more energy than the current 6 billion? Something tells me that if we restricted population to that level, ALL those people would be expecting a high standard of living?
I think we would still need conservation efforts, it would just seem so available, we'd probably burn it all up and impact the environment, even if there were fewer of us. Just an observation, I probably can't back it up, more of a gut feel.
Maybe not exactly on-topic, but I heard a great quote on Science Friday recently. They were talking about peak-oil, and one guy said,
'The Stone Age didn't end because we ran out of stones'. So, maybe at some point, what are now 'alternate' energy sources will just be viewed as 'better' energy sources? Maybe we will never 'run out' of oil?
-ERD50