This from Matt Yglesias
"And then something enormously predictable happened. Any time a depiction of growing inequality in the United States becomes popular, people who believe that increased inequality isn't bad, even if it's real, start arguing that it isn't real either. Scott Winship is one of the brightest lights of that school of thought, so he presented a long series of quibbles with both the Saez/Piketty data and Tcherneva's presentation of it which he framed as a debunking of their claims."
Matt ends with:
The bottom line is that while there is lots of room for arguing about the details of data selection, the conclusion that inequality is growing is not an eccentric discovery made by two French economists working with a particular source of income data. The broad trend is clear from a diverse set of data. Median household income growth has badly lagged per capita GDP growth, corporate profits as a share of national income have risen, and stock markets have reached record highs.
Outside the sphere of political debate, you also see the real world impact of inequality. Merrill Lynch recommends an investment strategy to its clients based on the growing economic clout of plutocrats, Singapore Airlines is now selling $18,400 first class cabin tickets, and observers think Apple is going to start selling a $10,000 watch. Conversely, Walmart is now primarily worried about competition from dollar stores. The executives at these companies are not hysterical liberals trying to drum up paranoia about inequality, they are trying to respond to real economic conditions — conditions that have entailed very poor wage growth paired with decent returns for those proserous enough to own lots of shares of stock.
Looping back to the beginning, the most striking fact about the entire dispute is that Winship himself does not disagree that inequality is at a very high level and that it has risen since the Reagan Revolution. He simply thinks it's wrong to obsess over this, and therefore that it's wrong to try to think up ways to dramatize it. But if you think that America is slipping into a doom loop of oligarchy then naturally you will want to dramatize the trend. Tcherneva's chart does that very well, which is exactly why it's so controversial.