[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/06/25/art.capitol.gi.jpg caption="Washington is debating the effects of oil speculation."]NEW YORK (CNNMoney.com) - It's the $64,000 question on Capitol Hill this week: what is responsible for the record escalation on oil prices?
Speculators have taken much of the blame. But on Wednesday, one of the nation's leading energy analysts said that it's more complicated than that and the cause is multi-faceted.
"In such circumstances as these, there is a tendency to seek a single explanation," said Daniel Yergin, in testimony before the Joint Economic Committee. "History, however, demonstrates that changes of this scale and significance result not from a single cause, but rather from a confluence of factors.