The NYTimes on energy prices:
Gasoline has slipped below $4 a gallon and is dropping fast as Americans drive less.
If the cause and effect implied is true people are making some long run decisions which is putting the U.S. on a new short run demand curve ... see: Demand vs Quantity Demanded. Dang! But, realistically, the long run isn't permanent (e.g., Chrysler K-cars to SUVs in the 1980s to 1990s).