A 1982 study[13] by American Airlines found that travel agents selected the flight appearing on the first line more than half the time. Ninety-two percent of the time, the selected flight was on the first screen. This provided a huge incentive for American to manipulate its ranking formula, or even corrupt the search algorithm outright, to favor American flights over its competitors in the results of flight search results, and the airline did not resist the temptation.