> A factory worker making cutlery or light bulbs will generate less money for the economy than the average Costco employee.

The good news is that we don't need to calculate the value of an employee, because the market itself makes it loud and clear: wages. The higher the wages, the higher the value. In any sane company, the less valuable an individual is to the bottom line, the less they get paid.

So then, if the wages of a factory job start to eclipse that of other fields, that's all the evidence we need of higher productivity/value/whatever-you-want-to-call-it.