The demise of ultra low-cost carrier Spirit Airlines is expected to add further upward pressure to U.S. fares, according to experts.

Launched in 1992, the company is responsible for the "Spirit Effect" in which bare-bones service opens up travel to a broader slate of customers otherwise priced out of the market.

Spirit's business model of stripped-down travel that includes no free meal service, baggage transport or other extras played a "unique and disruptive role in the industry," the U.S. Department of Justice argued in 2023, as it sought to block a merger with JetBlue.