By midafternoon yesterday, four low-cost airlines had matched the fare increase.
One by one, airlines matched it over the weekend.
Other airlines have matched the discounts to various degrees.
The nation's major airlines will match Eastern's fare cuts.
But other, stronger airlines have already matched America West's offer with similar promotions.
The other major hub-and-spoke airlines quickly matched its move.
Rival airlines that do not already have lower prices will probably match the fares of United, he said.
Air fares typically rise during the summer, and the large airlines usually match one another's fare increases quickly.
The other leading airlines, including United and Northwest, quickly matched the fare.
America West frequent fliers donated 1.6 million miles, which the airline matched.