according to an article in the Wall Street Journal, in early 2009, the prices of airline tickets in the U.S. had dropped by 40% at the same time that U.S. airlines had reduced the number of planes they had in services, thereby reducing the supply of airline seats. Use a demand and supply graph to illustrate how it is possible for the supply of airline seats available at every price to have declined at the same time that the equilibrium price fell.