Originally Posted by
cbn42
One thing to note is that intra-Europe flights might be cheaper due to the availability of hgih speed rail, which places downward pressure on airfares. In the US, ground transport options are lacking so the short-haul travel market is less competitive.
There's also Ryanair and other ULCCs helping to push down prices for intra-EU travel. A possibly better comparison here would be between Spirit/Frontier and said European ULCCs.