The average true price of a one-way airline ticket has increased by nearly 30 percent since 2008, and the presence of a low-cost carrier is not an accurate predictor of lower airfares, says a new study by Evergreen, Colorado-based Boyd Group International.

The data indicate that recruiting a “low cost” carrier to an airport may do little to lower overall fares…. Michael Boyd, chairman of the consulting firm, said that of the 10 highest-fare airports, eight have at least one low-cost carrier.