I imagine the effect on Junior pilot salary by senior pilots[1] could have some influence on the attractiveness of the profession.
From what I've read, people have mentioned that senior pilots who have great influence on union decisions, take a somewhat expectedly selfish attitude when it comes to negotiating salaries whereby junior pilots are left holding the bag. This gets repeated by junior pilots when they become senior pilots.
I was just going to post something along these lines: from what I've read, the aviation industry's possible "pilot shortage," actually translates to "airlines don't want to pay the market rate, or pay enough to encourage people to become pilots."
Which is usually the case in industries that claim a shortage of workers.
It's not the airline's fault if the pilot's union is optimizing for senior pilots' salarys.
In total Airlines pay pilots plenty, too much even. The issue is that unions have distorted the allocation. A fresh pilot will graduate with considerable debt yet garner a wage far below their economic value. Once they become senior they've "earned" the higher distorted wage. They may even still carry student debt. The situation thus becomes re-enforcing.
From what I've read, people have mentioned that senior pilots who have great influence on union decisions, take a somewhat expectedly selfish attitude when it comes to negotiating salaries whereby junior pilots are left holding the bag. This gets repeated by junior pilots when they become senior pilots.
[1]http://philip.greenspun.com/flying/unions-and-airlines