Over the past year, retail prices of gasoline and heating oil have increased by almost 50 cents per gallon. Diesel fuel prices have increased by more than 50 cents per gallon. One major cause of these dramatic increases in oil prices is the rising price of crude oil. In the United States, various types of crude oil are priced by using the price of West Texas Intermediate (WTI) crude oil as the benchmark. In early 2005, WTI prices were slightly above $42 a barrel, but by September 2005, they were at $70 a barrel. Oil prices have decreased then by a few dollars a barrel, but are still at historically high levels.

There are several factors that have contributed to the high oil prices we are experiencing today. The US accounts for between one fifth and one quarter of the world