http://www.usatoday.com/travel/colum...grossman_x.htm

My friend Laurie is continually angry with the airlines. When she buys a ticket for a last-minute business trip, she often pays considerably more than passengers who purchased tickets far in advance. "Why should business travelers subsidize leisure travelers who can book far in advance?" she asks.
I feel for Laurie, and all business travelers. They have always paid more for airline tickets than leisure travelers. But I cannot agree that business travelers subsidize leisure travelers. In fact, it is the other way around. Leisure travelers actually help lower ticket costs for business travelers. "How can that be when business travelers are paying so much more?" you might ask. The answer is in the math.