The paper concentrates on income inequality in the USA, both pre and post tax, including benefits through redistribution.

He exhibits the share of national income for the bottom 50% over time

The second image shows real income for the botton 50% flattening in the late 80s and that it has not recovered from the 2008 recession

The third is the share of the national income going to the top 1%, showing steady increase.

A paper in 2016 by Saez and Zucman at
https://eml.berkeley.edu/~saez/SaezZucman2016QJE.pdf
addresses wealth as opposed to income: