In June 2008, the U.S. retail gas price jumped from $3 to $4 a gallon. This is a 33% increase in price from January 2008. During that time, the total quantity of gasoline purchased fell by 3%. Supplies of gasoline produced also decreased from 1 million barrels to 800,000 barrels. No viable substitute has been created to replace gasoline.
How do you calculate for producer surplus?