I would say in Luton's case migration has fueled most of Luton's expansion. It started off with young men looking for work, then their girlfriends and wives came over. Now it is an equal mix of young and middle aged people who bring their parents over here to live. Those numbers should slow down but it won't stop.
As for the British living in the UK taking holidays abroad, I can see a drop in numbers as belts are eventually tightened. There then are foreign holidaymakers, which is a rising market so growth should come from there. That just leaves business travel but Luton is not an airport that is focused on business travel. Maybe they will have to raise their game if they want to see 25 million passengers?
Last edited by LTNman; 14th Aug 2017 at 13:54.