As far as I know, some universities do not allow their professors to use the textbooks written by them in their classes. Or at least they have some kinds of regulations on it. The rationale behind that is that there may be some ethical and financial issues with it because a professor gets an author's royalties for selling his or her books to students.
My question is:
A professor, however, works hard to write a textbook, and nobody knows his or her book better than the professor. Thus, the professor is the best person to use his or her authored textbook. It is somewhat strange that a professor can write a textbook but he or she is not allowed to use it. Also, a professor has academic freedom to choose his or her textbooks. Is it so much unethical for a professor to get his or her royalties for his or her hard work?
If you feel that a university must regulate a professor’s use of the textbook that he or she authored, what is the best approach? One possibility is to make the professor give up his or her royalties and donate them to his or her university. An alternative is to give a special discount on books to students by not taking the author's royalties.
Another possibility is to use of a department or a university-wide committee on the use of the textbook. Such committee reviews if the textbook authored by the instructor has no problem with using it (e.g., appropriateness of content for a class and the existence of financial gains by the instructor).
What is your opinion on this issue?