Listen to this podcast interview of Kaplan, he describes his new paper where he disputes the idea that CEOs are "gaming" the system by hiring each-other. The data is pretty convincing that CEO pay rates are increasing at the same rate as other skilled labor (lawyers, doctors, bankers, software engineers, etc).
http://www.econtalk.org/archives/2011/11/kaplan_on_the_i.htm...
(The "gotcha" is hedge fund managers, which have skyrocketed past everyone else)