I think that hints to how these pay bands come to be within a company though, it's not a transparent and liquid market with a bid/ask spread and a clearing pric

I think that hints to how these pay bands come to be within a company though, it's not a transparent and liquid market with a bid/ask spread and a clearing price. In practice the company decides a band that they think gets people in the door. HR gets involved, and management settles for a 0-2% inflationary increase YoY rather than the marginal rate. If you combine this with one employer bordering on a monopsony for buying a particular category of labor - then pay won't move in proportion to productivity.