Quote from TraderZones:
Oil was hit by supply and demand. So is everything else. Some things spike, drop and some lag for years.
But in the long run, inflation is the explanation why the dollar is worth 3% of 1913. But purchasing power has increased, not decreased.
Oil didn't shock (in that case) because of supply or demand, it shocked because of the devalued dollar, that's all I'm trying to get at. Supply and demand was at whatever point it was at, but the value of the currency paid de facto for oil, USD, was damaged, so OPEC raised prices to compensate. Neither supply nor demand changed prior to the oil shock.