Over the past decade, airlines have added more premium travel capacity than ever. Walking down the aisles of a Boeing 787 or Airbus A350 operated by any major US airline today will typically involve passing through a lengthy business class cabin (one with enough seats to account for around half of the plane’s total floor space) and then through an ever-growing premium economy cabin. Economy cabins continue to grow smaller, as airlines continue to have more and more premium seats in their aircraft cabin configurations.