Aviation U.S. network airlines make big effort to match no-frills carriers By Robert Silk / January 04, 2016 Share 1 -- The lowest fare offered by American, Delta and United was down by 23% year-over-year as 2015 drew to an end, according to an analysis conducted by the travel and aviation consulting firm Harrell Associates. Company president Bob Harrell said he believes the data reflects efforts by the Big Three to compete with growing competition from low-cost carriers Spirit, Frontier and Allegiant.“One of the reasons that fares go up and down, especially on the leisure end, is because a low-cost or ultra-low-cost carrier enters or leaves the market,” he said. “The largest carriers have made a conscious decision that they are not going to allow them to have exclusivity on the ultra-low fares.”Harrell Associates’ Airfare Report, which the firm produces weekly, crunches data on 280 major one-way services offered by American, Delta and United. The report from Dec. 21 showed that on average for those routes, the lowest one-way fare was down 23%, to $87.In some markets, the drops were even sharper. The lowest average fare from the Big Three on routes going to and from Chicago, for example, was down 54%, while the lowest fare on routes in and out of Philadelphia had declined by 48%.All three major carriers are offering at least some fares for far less than they did a year ago, the analysis also shows. On average, the lowest fares offered by American were 28% lower on Dec. 21 than they had been a year earlier. For United, the reduction was 27% and Delta 15%.Harrell said the drop in the lowest fare is among the largest he has seen since his company began producing the weekly report in its current format 10 years ago. The low cost of fuel, he added, has given the major airlines more freedom to offer at least some especially inexpensive seats as they compete with the low-cost carriers. Still, the steep decline in lowest airfare is not reflective of the overall industry trend. In November, the domestic fare was down slightly less than 2% compared with a year earlier, according to ARC. Meanwhile, Harrell Associates found that the Big Three's priciest economy fare (refundable, offered three days or less before departure, no minimum stay) had increased by 2% on Dec. 21. These flexible fares are most likely to be purchased by business travelers.The varying fare approaches taken by the Big Three U.S. airlines are indicative of public statements their executives have made in recent months about the need to compete for both high-end customers and price shoppers.