A source from the linked article: https://www.journals.uchicago.edu/doi/10.1086/685594

> “Pass-through” businesses like partnerships and S-corporations now generate over half of US business income and account for much of the post-1980 rise in the top-1% income share.

This is a quote of the article he linked:

https://www.npr.org/sections/planet-money/2026/09/14/g-s1-14...

In turn it links the source: https://www.journals.uchicago.edu/doi/10.1086/685594