Following the recent decision by the Justice Department to start investigating whether major airlines might be colluding in their capacity decisions, the Associated Press has conducted an analysis of major U.S. airports that finds industry consolidation seems to be having an impact on competition.

As a result of that diminished competition, “passengers appear to be paying the price in higher fares and fees,” AP said.

Analyzing data from a firm that tracks airline schedules, AP said that over the past decade, the number of U.S. airports where a single airline controls a majority of the seats for sale has risen from 34 to 40 of the 100 largest airports. And one or two airlines control a majority of seats at 93 of those airports, up from 78 a decade ago, AP said.

During that same time, the analysis found that domestic fares have gone up 5 percent — but that doesn’t take into account the wave of new passenger fees that airlines started to implement seven years ago, which have brought them billions of dollars in added revenues that didn’t exist before.

Airline mergers have been major factors in market control in recent years, AP noted. For example, since AirTran merged into Southwest and scaled back at Atlanta, Delta’s market dominance there has increased to 80 percent of seats available, and average domestic fares there went from 6 percent below the national average to 11 percent above.

At Philadelphia, US Airways used to control 66 percent of capacity; since its merger with American, AA/US Airways controls 77 percent, and airfares have gone up accordingly.

American has also increased its market share at San Francisco, where it now ranks in the number two spot after United. Ranking below AA, in order, are Virgin America, Delta, Southwest, Alaska and JetBlue according to an SFO spokesperson.

The AP analysis noted that the reverse trend is happening at a few airports, like Denver, where Southwest’s big buildup in recent years led to a reduction in United’s dominant market share there, and fares that are now 15 percent below the national average. It also cited Seattle, where Alaska and Delta are both adding capacity in a battle for market dominance. 

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