Daniel Yergin, vice chairman of HIS, comments on the importance of the U. S. as the swing producer in oil prices following Saudi Arabia determination to not cut oil output. Yergin said, "What kind of prices do you need to keep it going?" "What does it mean when you say the U.S. is the new swing producer? It's much easier to swing down than swing up." By mid April 2015 oil prices have rebounded from an over 50% decline since June, 2014. West Texas Intermediate crude futures were trading at about $55 per barrel on Monday morning, April 20th. U.S. oil production remains close to 40-year highs, even with the decline in oil price.