[lordnacho]

The way I see it marginalism gives us some numbers, but given some constraints. For example, you can't be sending kids down your mine. The market then gives you an alternative figure for the price of diamonds. The question then is what constraints are reasonable. That whole discussion is a debate about our values in another sense.

About consultants (the MBB/B4 kind), all I can really say is that they tend to confess on their own that they don't provide much value. Everyone I know in the profession seems to say so. They find it utterly baffling that 23 year olds can be rented out at about 6x their salary to do presentations to managers with decades of experience. They often tell you that they are simply rubber stamping some internal decision with some nice slides, and that the slides have no real insights.

There doesn't have to be a contradiction either, it may well be that these guys are scarce like diamonds, but also like diamonds, they aren't really valuable in another sense.