ckip
Here is a reference chain:
https://www.nytimes.com/2017/11/17/upshot/income-inequality-...
Tldr: "Almost all of the growth in top American earners has come from just three economic sectors: professional services, finance and insurance, and health care, groups that tend to benefit from regulatory barriers that shelter them from competition.
The groups that have contributed the most people to the 1 percent since 1980 are: physicians; executives, managers, sales supervisors, and analysts working in the financial sectors; and professional and legal service industry executives, managers, lawyers, consultants and sales representatives."
There is a huge demand for cheap lawyers -- basically people who know rules of procedure and basic law. They don't exist, in part because law schools don't teach enough practical skills to be able to practice without malpractice.
Founders excluded, of course.
The only domain requiring unique productive skills is doctors... The rest is all market manipulation.