Last week, a round-trip airfare on Northwest Airlines to San Francisco could be booked for $118, about one-third of its usual cost, as Northwest responded to a special, $49 each-way promotion by low-fare carrier Sun Country.
That type of dogfight is becoming more common at large U.S. airports as more of them see low-fare carriers establish a significant presence.
"The airline industry is likely the most competitive it has ever been," concludes an analysis by former senior U.S. Department of Transportation officials. More passengers "are benefiting from increased numbers of competitors, increased presence of low cost airlines and lower fares."
While the trend is affecting Minneapolis-St. Paul, it is proving slower to take hold than in most major cities.
Travelers beginning their trips at Minneapolis-St. Paul International Airport on average pay 21 percent more than travelers starting at other hub airports because of the relative lack of low-fare carriers here, according to the former Transportation Department officials' report.
With increased service from low-fare carriers, the so-called "hub premium" isn't as steep as it used to be in the Twin Cities. Twelve years ago, the premium was 38 percent.
Minneapolis-St. Paul "now ranks fourth-highest," said Patrick Murphy, co-author of the competitive analysis and a former deputy assistant secretary for aviation at the Transportation Department. "It's not in the ranks of the worst, but there is still a premium."
Murphy said the strength of Northwest Airlines in this market contributes to the fare premium by keeping smaller carriers out of the market. In 2006, Northwest flights accounted for 76.5 percent of takeoffs and landings at the airport.