Figure 10-4 Graph (a) Graph (b) A graph of price, P, versus quantity, Q, shows a supply curve, S, rising linearly from the origin, and a demand curve, D, descending linearly. The curves intersect at (Q subscript 1, P subscript 1). A graph of price, P, versus quantity, Q, shows a supply curve, S, rising linearly from the origin, a second supply curve, Social Cost, rising linearly above the first supply curve, and a demand curve, D, descending linearly. Curve D and Curve S intersect at (Q subscript 3, P 3 b). Curve D and Curve Social Cost intersect at (Q subscript 2, P subscript 2). Point (Q subscript 3, P 3 a) is marked at a point on Curve Social Cost to the right of the intersection of Curve Social Cost and the demand curve. The quantity Q subscript 3 is consistent with both P 3 b and P 3 a, and those points on the supply and the social cost curves, respectively. Graph (c) A graph of price, P, versus quantity, Q, shows a supply curve, S, rising linearly from the origin, a demand curve, D, descending linearly, and a second demand curve, Social Value, descending linearly