-PJ
No y'all are misunderstanding what Obama said. Obama didn't say the low prices caused the bad economy. He said the low prices were the result of the bad economy.
And Obama said Romney could cause more low oil prices by crashing the economy with his policies. Not that Romney policies would lower oil prices and cause a crash, but that his policies would crash the economy, and oil prices would fall as a result of the bad economy. Thus Romney would successfully bring oil prices back down by crashing the economy.
I don't remember exactly what Romney said about prices, other than that they had increased due to Obama's policies.