It isn't so simple, because there are many ways of dividing up the work that's going to be done into job roles (and the division tends to be industry-wide, rath

It isn't so simple, because there are many ways of dividing up the work that's going to be done into job roles (and the division tends to be industry-wide, rather than done separately within each company). The people doing the hiring may have enough information to produce an efficient market for a given job role, but I don't think the mechanism for the selection of job roles looks much like a supply-and-demand market. Consider system administration. As a simplified example, you could have one equilibrium in which you have one low-skill employee for each 50 computers, or a different equilibrium where you have one high-skill employee for each 500 computers. If the industry as a whole settled on the first, a particular company would find it hard to switch to the second: it would be hard to even gather information about how well it would work, because the operating systems available would be designed for the lower levels of automation that the first model implies. In cases where two equilibria are viable, I think where we end up can depend on whether the employers feel that a given sort of job "ought" to be a high-paid professional one or not.