An Applicable Chapter in Freakonomics
Why Crack Dealers Live with their Mothersdemonstrates interesting economic similarities between dealing crack and flying airplanes.
There is a vast pyramid from associate gang members paying monthly membership to street level dealers making little more than welfare to the local gang leader making $100K tax free to the directors making millions.
The authors characterise this situation as a tournament with low level aspirants tolerating unliveable wages and dangerous working conditions for a shot at the very well paid gang leader position.
Instructors and feeder airline pilots tolerate the same low wages and poor working conditions as a means to get into a well paid jet job.
This is very much a North American situation as many young people can pay their way onto that low rung of the career ladder. Any flying position can attract hundreds of resumes. In earlier times, North American airlines were able to fill a major portion of their positions from retired military, but that pool has shrunk considerably.
In Europe, self-sponsorship is far more expensive; so we find many airlines taking on cadets and training them ab initio.