Business class is a much more significant upgrade from economy class for long-haul flights, in contrast to a regional or domestic flight where business class offers few relative advantages over economy class. The innovations in business-class seating, incorporating features previously only found in first class (see below), has narrowed the comfort and amenities gap with traditional first-class seats. These advances and added features to business class, as well as the late 2000s recession, have caused some airlines to remove or not install first-class seating in their aircraft (as first-class seats are usually double the price of business class but can take up more than twice the room) which leaves business class as the most expensive seats on such planes, while other airlines have reintroduced first-class sections as suites to stay upmarket over contemporary business class.[15]