Figure 23.8 depicts the supply curv

Figure 23.8 depicts the supply curve for gasoline if all oil were to sell for
the world price of $15 a barrel, and if all oil were to sell for the domestic
price of $5 a barrel. If domestic oil actually sells for $5 a barrel and foreign
oil sells for $15 a barrel, then the supply curve for gasoline will coincide
with the $5-a-barrel supply curve until the cheaper domestic oil is used up,
and then coincide with the $15-a-barrel supply curve.