Comment by sokoloff

I'm a manager of software engineers. I have absolutely no intention of paying engineer B the same as half-as-productive engineer A.

Figuring out the best way to determine productivity is still a hard problem, but I think it's a category error to think that productivity gains go exclusively to the company.

If all (or even most) of the engineers on your team who were previously your equal become durably twice as productive and your productivity remains unchanged, your income prospects will go down, quite possibly to zero.