How do you figure out the productivity of employees paid to think?
In the old days, productivity was measured by a range of quantitative measures, quantity, cost, conformance to standard, cycle times, and so on. Now, when the productivity is ideas, improvements, removal/adjustment of past practices, and the “joining of the dots” it is harder.
When there is a clearly available substitute, the market dictates the price, it costs $60 an hour to get your car serviced, but where there are no obvious substitutes, it is more a matter of what the market will bear. What is it worth to hear a competent musician play a cover? What would it be worth to hear the piece played by the originator?
Competent musicians are relatively common, those who can create something worth covering are rare, and are paid accordingly, and the time it took to create the piece plays no part in the calculation, it is all about the value created, and measuring that is a whole new ballgame.