The marketing environment of the airline industry will certainly remain uncertain and difficult. The established trends towards deregulation and liberalisation will continue, and, at least towards the end of a 10year timescale, may encompass the long-overdue changes in ownership and control rules. These will allow for more cross-border merger and acquisition activity and result in international aviation finally taking its place amongst other global industries. Airport slot allocation will almost certainly come to be based more on market principles, though the question of who should keep the proceeds from slot sales will always be a difficult one. Environmental issues will become even more important. Carriers will face justified limits on their growth and freedom of action unless they can demonstrate that they are taking all possible steps to minimise the environmental impact of their activities, even if these steps involve substantial costs.