A great article on why Pay Transparency really works:

Huet-Vaughn concedes he has no idea why this happened. But he has a great theory: We don’t care as much about the amount we make as long as we know we’re not being taken advantage of. And not knowing what other people earn is, de facto, a breeding ground for doubt.”

Well, this feeling might actually kick in only after a certain ceiling has been penetrated but this is a great insight, nevertheless.