This is the wrong question. CEO's are probably no more overpaid than many other people who can fool others into paying what they ask. "The worker is worth his hire." They are however wrongly paid. Their compensation should be subject to proxy fight every year, which keeps stockholders aware and interested. Labor, capital, managemant; each always thinks the others get too large a piece of the pie.
It's a vicious cycle and a very complicated issue. I don't know what the government can do about this except aggressively police any public corporation who violates IRS, DOL, FASB, etc standards. Also, negative publicity by private watchdog groups would be of benefit.