Pressures of supply and demand act directly on the prices of airline tickets. as the seats available on the plane begin to fill, airlines raise the price. if seats on a flight do not sell well, an airline may discount the tickets or even cancel the flight. allie henrich, a byu-idaho student, wanted to predict the price of tickets 14 days before a flight based on the price of tickets listed 90 days before the same flight. for her study she compared the prices of one-way flights from london's heathrow airport to various destinations in europe. using travelocity, she recorded the lowest published fares for 90 nonstop midweek flights 90 days in advance and then found the lowest published price for the same destination again 14 days in advance.