At least so they say in the article Where airfares are taking off. Some excerpts from the article:
“For travelers, the math points to substantial price hikes where carriers merge and dominate.
It’s the fallout from airline mergers, and the planned combination of American Airlines and US Airways LCC -0.31% could bring a new round of hefty fare increases. When two competitors combine to dominate prime routes, those markets tend to bear the brunt of higher prices.
Consider United Airlines and Continental Airlines, which used to compete for customers flying between Chicago and Houston, for example. After the two airlines merged in 2010, the combined company, which took the United name, now carries 79% of the traffic traveling between Houston’s Bush Intercontinental Airport and Chicago’s O’Hare Airport, not counting connecting passengers. United’s average fare on that route soared 57% in the three months ended September 2012 compared with the same period three years earlier, according to Department of Transportation data compiled by PlaneStats.com. By comparison, United’s total average domestic price per mile over the same three-year period went up only 16%.
“There are definitely routes where competition will be significantly eliminated,” said Diana Moss, director of the American Antitrust Institute, a nonprofit group that aims to promote competition, at a March 19 Senate hearing on the American-US Airways deal.
The Delta-Northwest and United-Continental mergers resulted in “substantial elimination of competition on some very important routes,” Ms. Moss said. Fare increases resulted—”and some pretty significant ones. We also saw very few fare decreases.”