A journey with a connection often costs less than the non-stop on the same route, despite taking longer and using more fuel. The pricing reflects competition rather than cost.
The non-stop carrier holds an advantage
Most travellers prefer the non-stop and will pay a premium for it, because it saves hours and removes the risk of a missed connection.
An airline operating the only non-stop on a route therefore prices against that preference rather than against its own costs.
The premium it can charge depends on how much time the connection adds, which is why the gap is widest on routes where connecting adds most.
Connecting carriers are competing for spill
An airline routing a passenger through its hub is offering an inferior product and knows it, so it competes on the only dimension available.
The passenger it wins would otherwise have flown entirely with a competitor, so the relevant comparison for that airline is revenue against nothing at all.
That logic supports a lower fare than the route's costs alone would suggest, particularly on flights that would depart with empty seats regardless.
Hub economics change the calculation
A hub airline fills its aircraft with passengers from many origins and many destinations, few of whom are travelling between the hub and anywhere.
Each additional connecting passenger contributes revenue on two flights that were operating anyway, so the marginal cost of carrying them is low.
Local passengers travelling to or from the hub city itself pay more, because they have fewer alternatives and are less price sensitive.
The costs sit with the passenger
The saving is real but it is paid for in time, in additional exposure to disruption and in the physical experience of an extra departure and arrival.
Connection time also matters, since a short connection risks a misconnect while a long one can add most of a day.
Where both flights are on one ticket the airline carries the rebooking obligation, which is a substantial protection that separate tickets do not provide.
When the connection is worth taking
On long-haul routes the absolute saving can be large enough to justify several additional hours, particularly on a leisure trip with flexible timing.
On short routes the saving is usually small while the proportional time penalty is large, so the non-stop wins more often than travellers expect.
The other consideration is what a delay would cost, since a connection missed at the start of a short trip removes a meaningful share of the trip itself.