Sex for promotions and raises.

[moorobot]

Well, when you take into account the high level of natural attraction women have to males in positions of power with the fact that the sleeping around will likely lead to other benefits in this situation any economist could tell you how common this is. Statistical Studies will tell you the same
PS I'm on the left in politics if anybody is, and not every woman in a position of power has achieved that position via this method by any means.