In 2013, the equilibrium price and quantity of good X were $6 and 2 million pounds. Because of strong demand in 2014, the equilibrium price and quantity of good X rose to $8 and 4 million pounds. Then in 2015, new technologies increased supply, reducing the equilibrium price to $7 and raising quantity to 6.

Draw the 2013 and 2015 supply and demand curves for good X in the chart below, assuming that both curves are linear. (4 curves to draw since they all shifted once.)

How large was the consumer surplus, the producer surplus, and the gains from trade in 2013 and 2015 (in $ millions)

Price $12 11 -NWAUANODC O 1 2 3 4 5 6 7 8 9 10 1 1 12 Millions of Pounds