Emirates and other Middle East carriers have expanded aggressively into the "kangaroo" route between Britain and Australia. In 2013, Qantas and Emiratesagreed to coordinate schedules, advertising, and pricing, and share revenues. Qantas changed its kangaroo stopover from Singapore to Dubai. Subsequently, Virgin Atlantic withdrew from the kangaroo market.

4> If Qantas and Emirates raise prices, how should other airlines respond?