Are taxes or crude oil prices to blame for expensive petrol?

PETROL prices have risen steeply in rich countries, triggering heated arguments about whom or what is to blame. America's energy department recently blamed a jump in petrol prices of 3.1 cents per gallon in the space of seven days on the political unrest in Egypt affecting crude oil prices. Japan's government blamed the high price of crude oil for its tenth weekly price increase at the pump. The British government has given the same explanation for price increases averaging 15% in the year to January. But with the oil price still at only two-thirds of its peak in mid-2008, this is not the only cause—as the three charts below show.