Salary transparency at all levels would help quite a bit. The SEC rules around required pay package disclosure for execs is a major reason that CEO pay spiked in the 90s. You gain a good amount of negotiation leverage when you know exactly how much each or your peers are making.
We're working on salary transparency across different levels with our website http://levels.fyi (mainly software engineering to start).
We were thinking of launching an executive version of our site. Still in our plans down the road, but it'd require people willing to submit their compensation to our site in a verified way. We're still brainstorming, but there's a lot more nuance at upper levels where people negotiate across way more things than just strictly compensation.
