The 9/11 terrorist attacks caused the U.S. airline travel demand curve to shift left by an estimated 30% (Ito and Lee, 2005). Use a supply-and demand diagram to show the likely effect on price and quantity (assuming that the market is competitive). Indicate the magnitude of the likely equilibrium price and quantity effects-for example, would you expect equilibrium quantity to change by about 30%? Show how the answer depends on the shape and location of the supply and demand curves.