Setting the price of a perishable seat · Ceded (since 1992)

In February 1992, American Airlines published an account of its yield management system in Interfaces, describing models that set overbooking levels, discount allocation and connecting traffic, and crediting them with 1.4 billion dollars of revenue over three years.

A sales manager once set fares in a published tariff and changed them a few times a year. Yield management turned the price into a moving answer, recomputed for every seat on every departure as the date approaches, at a frequency and detail no committee can reproduce. The method spread out of aviation into hotels, car hire, rail, concert tickets and online retail, so that a posted price is now usually a machine's output. What people keep is the shape of the fare structure, the rules about what may be varied and what may not, and the answer owed to a regulator or a customer who discovers that two people paid different amounts for the same thing at the same moment.