America’s Low-Cost Airline Playbook Is Broken. Here’s What the Next Model Looks Like.

Low-cost carriers in the U.S. have had a brutal few years: Spirit, Frontier, Allegiant, and Sun Country posted negative operating margins in three of the four quarters through Q2 2025.

The global comparison underscores how weak this is. Across Europe, Asia, the Middle East, and Latin America, low-cost carriers delivered consistently positive — often double-digit — margins.

Two forces are driving the U.S. underperf