A Fall in the Price Increases Consumer SurplusA fall in the price of a computer from $4,300 to $1,500 leads to an increase in the quantity demanded and an increase in consumer surplus. The change in total consumer surplus is given by the sum of the shaded areas: the total area below the demand curve and between the old and new prices. Here, the dark blue area represents the increase in consumer surplus for the 200,000 consumers who would have bought a computer at the original price of $4,300; they each receive an increase in consumer surplus of $2,800. The light blue area represents the increase in consumer surplus for those willing to buy at a price equal to or greater than $1,500 but less than $4,300. Similarly, a rise in the price of a computer from $1,500 to $4,300 generates a decrease in consumer surplus equal to the sum of the two shaded areas.