Income inequality generally just means that different people make different amounts of money. It's quite obviously true, and has increased quite a lot in the U.S. in recent decades.

You mean to be dismissive of the wage gap or pay gap, or maybe more specifically the gender wage gap, or male-female income disparity.

Wikipedia seems to indicate that there is a healthy body of research on the topic, with researchers reaching different conclusions:

http://en.wikipedia.org/wiki/Gender_pay_gap_in_the_United_St...

Every study I have ever seen that says there is a wage gap, compares people in different roles and industries which seems stupid. That's like complaining that a teacher doesn't earn as much as a CEO.