actually to put the discussion into perspective, it is the type of job you are in that determines what salary you are getting now.

The risk, the knowledge involved and the career lifespan, I would say are the 3 key factors.

Risk - if the job is risky, say working in the refinery, there will be a premium in the salary associated with this.

Knowledge involved - if the job requires an intrinsic knowledge that you possess, there again is another premium tagged to your salary

Career lifespan - if this job only lasts 10 years, take for example a footballer, there has to have a premium to encourage someone to take this career path.

Not sure if everyone agrees?