The prices posted on gas station signs across Lawrence have gone up by more than 70 percent since the war in Iraq started.

Alexandre (Sasha) Skiba, an assistant professor of economics at Kansas University, says the war has played some role in the rise in gas prices.

When the United States invaded Iraq on March 19, 2003, the average price of regular unleaded gasoline in Lawrence was $1.69 a gallon.

Four and half years later, as oil prices continue to climb closer to the $100 a barrel mark, the price of unleaded gasoline in Lawrence – as of Thursday – was about $2.94 a gallon.

Gasoline prices peaked in May of this year with the average price of regular unleaded gas at $3.33 a gallon.

Iraq accounts for about 3.5 percent of the world’s oil supply, so the hardship of getting the oil out of the country does contribute somewhat to higher prices. But the more pressing issue is the fear of instability in the Middle East.

“The uncertainty is a bigger effect than the actual reduction in supply,” Skiba said.

A bigger factor in the rising price is a good old fashion case of too much demand and not enough supply, Skiba said. Developing countries such as India and China and those in Eastern Europe and South America are using more oil than before.

“I still think the demand is the main driving force,” he said.