> The fact that different professions earn different amounts of money is, in fact, an indicator that the higher paying professions have a shortage of people able to perform the work.

If we have 2000 people, we need 1000 doctors and 1000 secretary and it takes 8 years of training to be the former and 1 year for the later, won't doctors be paid more even without shortage to take into account risks and length of studies?