system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are college professors who require students to pay for textbooks they work on not barred by anti-trust laws?

In the United States, it's extremely common for a professor to require students to pay for books for a class where the professor has paid for the book, or they receive some form of compensation for books sold.

This seems like a direct violation of anti-trust laws: To have someone requiring the purchase of a product, that they receive compensation for, in order to pass an educational course. Even at a private college.

How the hell does this keep going on? I would also like to know if the same applies to situations where the school and the textbook company are in a business deal.
gpt
Anti-trust laws deal with the domination of a sector by a specific industry.  If you don't want to pay for the book, you're free to take the course from another professor or another college.  Anti-trust laws really have no bearing.