If I were making a good deal more than my peer what do I gain by being fair and honest. What makes it fair? Why shouldn't I make more or less by the skill of negotiation? I've not yet read a reason for the top paid people to talk about their salary. It seems they would have more to risk than gain and it would hurt them in the next negotiation. Not having spoken about my salary I've got no idea if I make more or less.…
So when an executive goes to another job they say "Hey, so and so makes that much money and that's what CEO is worth. Pay me more than that".
And hence we are where we are today when executives get paid a lot, given golden parachutes, etc.
I would imagine the same would go for any position of salaries are opened up.