Airlines reserve a handful of seats on each plane for those last-minute travelers who will pay top dollar to get to an important meeting or event.
Those last-minute travelers tend to be in the professional service fields, such as lawyers and consultants, a new study concluded.
Of the tickets purchased by such professionals, only 28% are booked more than 15 days in advance of the flight, according to a study by Concur, a Bellevue, Wash., company that sells corporate travel expense reporting services.
These fliers booked 26% of their flights within three days of departure.
"The volume of last-minute travel is higher in business services, which can likely be attributed to client meetings and activities that are more difficult to anticipate in advance," the study concluded.
On the other hand, travelers who work in higher education, such as university professors, are most likely to book early, with 69% of their tickets booked more than 15 days in advance, the study found. They booked only 7% of their flights within three days of departure.
Fliers in the retail and restaurant business booked 46% of their flights more than 15 days in advance and only 13% of tickets within three days of departure.
Various studies have suggested that the lowest price for a domestic airline is available about six weeks before departure.